Patent Publication Number: US-11654352-B2

Title: Information processing system, storage medium storing information processing program, information processing apparatus, and information processing method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The application is a continuation of U.S. application Ser. No. 16/749,245, filed Jan. 22, 2020, which claims the benefit of Japanese Patent Application No. 2019-157999, filed Aug. 30, 2019, each of which is incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The technology disclosed herein relates to information processing systems, storage media storing information processing programs, information processing apparatuses, and information processing methods for causing an object to perform an action according to a user&#39;s operation. 
     BACKGROUND AND SUMMARY 
     Conventionally, an input apparatus has been disclosed that is held by a user and allows a game process to be executed using an output of the input apparatus. 
     However, in a game using the above input apparatus, an input method that is performed by a user (hereinafter referred to as a “user input method”) may be limited. 
     With the above in mind, it is an object of this non-limiting example to provide an information processing system, storage medium storing an information processing program, information processing apparatus, and information processing method that can increase the variety of user input methods. 
     To achieve the above, this non-limiting example has the following features, for example. It should be understood that the scope of the present technology is defined only by the appended claims. To the extent of any inconsistency or conflict in disclosure between the description and the claims appended hereto, the claims shall prevail. 
     A non-limiting example configuration of an information processing system according to this non-limiting example includes a first input apparatus including a strain sensor, a second input apparatus including a motion sensor and different from the first input apparatus, and an information processing apparatus. The strain sensor provides an output corresponding to a force applied to at least a portion of the first input apparatus, the motion sensor provides an output corresponding to a motion of the second input apparatus. The information processing apparatus includes a computer that executes obtaining strain data corresponding to the output of the strain sensor and motion data corresponding to the output of the motion sensor, and executing first control on an object disposed in a virtual space based on the strain data, and second control on the object based on the motion data, the second control being different from the first control. 
     With the above configuration, the first control is executed on an object disposed in a virtual space based on the strain data corresponding to the output of the strain sensor of the first input apparatus, and the second control is executed on the object based on the motion data corresponding to the output of the motion sensor of the second input apparatus. The variety of user input methods using both of the first input apparatus and the second input apparatus can be increased. 
     The motion sensor may include an angular velocity sensor and/or an acceleration sensor. 
     With the above configuration, the motion of the second input apparatus can be easily calculated using an angular velocity and/or acceleration occurring on the second input apparatus. 
     The first input apparatus may further include a holding portion. The strain sensor may output the strain data corresponding to a force applied to the holding portion of the first input apparatus. 
     With the above configuration, the first control can be executed on the object based on a force applied to the holding portion of the first input apparatus. 
     The first input apparatus may be at least partially elastically deformable in response to an external force applied thereto. The strain sensor may provide an output corresponding to deformation of the first input apparatus. The first control may be executed based on deformation of the first input apparatus indicated by the strain data, and the second control is executed based on the motion data while the deformation of the first input apparatus is detected based on the strain data. 
     With the above configuration, the execution of the second control based on the motion data can be controlled according to an operation of deforming the first input apparatus. 
     The second control may be executed in different ways between when the force applied to the first input apparatus satisfies a predetermined condition and when the force applied to the first input apparatus does not satisfy the predetermined condition. 
     With the above configuration, the second control is executed in different ways, depending on whether or not a force satisfying a predetermined condition is applied to the first input apparatus. Therefore, the variety of user input methods can be further increased. 
     The second control may be performed so that the object is moved based on the motion data when the force applied to the first input apparatus satisfies the predetermined condition, and the object may not be moved, irrespective of the motion data having been obtained, when the force applied to the first input apparatus does not satisfy the predetermined condition. 
     With the above configuration, the action of the object is changed, depending on whether or not the force applied to the first input apparatus satisfies a predetermined condition. Therefore, the variety of user input methods can be further increased. 
     The second input apparatus may be attached to a user&#39;s body. The motion sensor may output the motion data corresponding to a motion of the second input apparatus caused by the user&#39;s stamping-foot action. A process of moving the object in the virtual space based on the motion data corresponding to a motion of the second input apparatus caused by the user&#39;s stamping-foot action, may be executed as the second control. 
     With the above configuration, the movement control of the object can be executed based on the user&#39;s stamping-foot action. 
     The first input apparatus may further include a motion sensor which outputs motion data corresponding to a motion of the first input apparatus. A process of changing an orientation of the object based on the motion data output from the first input apparatus, may be executed as third control. An in-game merit may be given to a user when the object has a predetermined orientation at a predetermined location in the virtual space. 
     With the above configuration, the third control can be executed on the object based on the motion of the first input apparatus. Therefore, the variety of user input methods can be further increased. 
     A deformation process of deforming the object based on the strain data, may be executed as the first control. A process of changing a way of deforming the object based on the motion data output from the second input apparatus, may be executed as the second control. 
     With the above configuration, the process of deforming the object while changing the way of deforming the object, using both of the first and second input apparatuses, can be executed. 
     A process of moving the object in a first direction based on the strain data, may be executed as the first control. A process of moving the object in a second direction different from the first direction, based on the motion data, may be executed as the second control. 
     With the above configuration, the process of moving the object in the second direction while moving the object in the first direction, using both of the first and second input apparatuses, can be executed. 
     The first input apparatus may further include a holding portion. The second input apparatus may be attached to a portion of a user&#39;s body. The strain sensor may output the strain data corresponding to a force applied to the holding portion of the first input apparatus. The motion sensor may output the motion data corresponding to a motion of the portion of the user&#39;s body to which the second input apparatus is attached. 
     With the above configuration, an operation can be performed based on a force applied by the user to the holding portion of the first input apparatus, and a motion of a portion of the user&#39;s body. 
     A shape of a target object disposed in the virtual space may be changed based on a positional relationship between the object and the target object. 
     With the above configuration, a shape of a target object can be changed by controlling the location of the object. 
     A process of moving the object along an outer periphery of the target object, based on the motion data, may be executed as the second control. A process of moving the object in a direction including at least a directional component toward inside of the target object, based on the strain data, may be executed as the first control. A process of changing the shape of the target object may be executed based on the positional relationship between the object and the target object. 
     With the above configuration, the target object can be easily deformed by allowing the second control of moving the object along the target object, and the first control of moving the object in a direction including a directional component toward the inside of the target object. 
     A process of continuing to move the object in the first direction, based on the amount of a force applied to the holding portion of the first input apparatus indicated by the strain data, may be executed as the first control. 
     With the above configuration, the control of moving the object in the first direction based on a force applied to the first input apparatus, can be executed. 
     The executing the first control and the second control may include assessing the shape of the target object at the end of a predetermined time limit. 
     With the above configuration, the user is allowed to easily recognize a game in which the shape of the target object is changed. 
     The first control may be executed when the strain data indicates that the amount of the force applied to the first input apparatus is greater than a first threshold, and the first control may be executed when the strain data does not indicate that the amount of the force applied to the first input apparatus is greater than the first threshold, and indicates that the amount of the force applied to the first input apparatus is greater than a second threshold smaller than the first threshold after the amount of the force applied to the first input apparatus has exceeded the first threshold. 
     With the above configuration, the control can be continued even when the force applied to the first input apparatus is reduced after the operation of applying the force. 
     The first control may be executed on the object, based on the amount of a force applied to the first input apparatus at a timing that a motion occurs on the motion sensor of the second input apparatus. 
     With the above configuration, control can be executed based on a time-series relationship between a motion occurring on the motion sensor of the second input apparatus and a force applied to the first input apparatus. 
     The first control may be executed, based on the amount of a force having been applied to the first input apparatus during a period of time from a timing that a motion occurs on the motion sensor of the second input apparatus to a predetermined time before, when the amount of a force applied to the first input apparatus at the timing that a motion occurs on the motion sensor of the second input apparatus is smaller than the amount of deformation of the first input apparatus having occurred during the period of time from the timing that a motion occurs on the motion sensor of the second input apparatus to the predetermined time before. 
     With the above configuration, the control can be continued, taking into account the case where the force applied to the first input apparatus is reduced at a timing that a motion occurs on the motion sensor of the second input apparatus. 
     The executing the first control and the second control may also include displaying an image indicating the amount of deformation of the first input apparatus while the first input apparatus is deformed. 
     With the above configuration, the amount of deformation of the first input apparatus can be presented to the user. 
     This non-limiting example may be carried out in the forms of a storage medium storing an information processing program, information processing apparatus, and information processing method. 
     According to this non-limiting example, the variety of user input methods can be increased. 
     These and other objects, features, aspects and advantages of the present exemplary embodiment will become more apparent from the following detailed description of the present exemplary embodiment when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram showing a non-limiting example of apparatuses included in a game system  1 , 
         FIG.  2    is a diagram showing a non-limiting example of a state where a left controller  3  and a right controller  4  are attached to a main body apparatus  2 , 
         FIG.  3    is a diagram showing a non-limiting example of a state where each of the left controller  3  and the right controller  4  are detached from the main body apparatus  2 , 
         FIG.  4    is six orthogonal views showing a non-limiting example of the main body apparatus  2 , 
         FIG.  5    is six orthogonal views showing a non-limiting example of the left controller  3 , 
         FIG.  6    is six orthogonal views showing a non-limiting example of the right controller  4 , 
         FIG.  7    is a block diagram showing a non-limiting example of an internal configuration of the main body apparatus  2 , 
         FIG.  8    is a block diagram showing examples of internal configurations of the main body apparatus  2 , the left controller  3 , and the right controller  4 , 
         FIG.  9    is a diagram showing a non-limiting example of a ring-shaped extension apparatus, 
         FIG.  10    is a block diagram showing a non-limiting electrical coupling relationship between components included in the ring-shaped extension apparatus  5 , 
         FIG.  11    is a diagram showing a non-limiting example of a belt-shaped extension apparatus  6 , 
         FIG.  12    is a diagram showing how a user uses the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6 , 
         FIG.  13    is a diagram showing a non-limiting example of how, in a first non-limiting example game, the user operates the ring-shaped extension apparatus  5 , 
         FIG.  14    is a diagram showing a first non-limiting example of a game image displayed on a stationary monitor  9  according to the user&#39;s operation in the first non-limiting example game, 
         FIG.  15    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the first non-limiting example game, 
         FIG.  16    is a diagram showing a non-limiting example of a data area contained in a DRAM  85  of the main body apparatus  2  in the first non-limiting example game, 
         FIG.  17    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1  in the first non-limiting example game, 
         FIG.  18    is a subroutine showing a specific non-limiting example of a vertical movement process performed in step S 505  shown in  FIG.  17   , 
         FIG.  19    is a subroutine of a specific non-limiting example of a cutting process performed in step S 506  shown in  FIG.  17   , 
         FIG.  20    is a diagram showing a non-limiting example of how, in the second non-limiting example game, the user operates the ring-shaped extension apparatus  5 , 
         FIG.  21    is a diagram showing a first non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the second non-limiting example game, 
         FIG.  22    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the second non-limiting example game, 
         FIG.  23    is a diagram showing a third non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the second non-limiting example game, 
         FIG.  24    is a diagram showing a non-limiting example of a data area contained in the DRAM  85  of the main body apparatus  2  in the second non-limiting example game, 
         FIG.  25    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1  in the second non-limiting example game, 
         FIG.  26    is a subroutine showing a specific non-limiting example of an extension and shortening process that is performed in step S 605  shown in  FIG.  25   , 
         FIG.  27    is a subroutine of a specific non-limiting example of a tilting process that is performed in step S 606  shown in  FIG.  25   , 
         FIG.  28    is a subroutine of a specific non-limiting example of a walking process that is performed in step S 607  shown in  FIG.  25   , 
         FIG.  29    is a diagram showing a non-limiting example of how, in a third non-limiting example game, the user operates the ring-shaped extension apparatus  5 , 
         FIG.  30    is a diagram showing a first non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the third non-limiting example game, 
         FIG.  31    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the third non-limiting example game, 
         FIG.  32    is a diagram showing a third non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the third non-limiting example game, 
         FIG.  33    is a diagram showing a non-limiting example of a data area contained in the DRAM  85  of the main body apparatus  2  in the third non-limiting example game, 
         FIG.  34    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1  in the third non-limiting example game, 
         FIG.  35    is a subroutine showing a specific non-limiting example of a swing setting process performed in step S 307  shown in  FIG.  34   , 
         FIG.  36    is a subroutine of a specific non-limiting example of a swing display process performed in step S 311  shown in  FIG.  34   , 
         FIG.  37    is a diagram showing a non-limiting example of how, in a fourth non-limiting example game, the user operates the ring-shaped extension apparatus  5 , 
         FIG.  38    is a diagram showing a first non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the fourth non-limiting example game, 
         FIG.  39    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the fourth non-limiting example game, 
         FIG.  40    is a diagram showing a third non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the fourth non-limiting example game, 
         FIG.  41    is a diagram showing a non-limiting example of a data area contained in the DRAM  85  of the main body apparatus  2  in the fourth non-limiting example game, 
         FIG.  42    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1  in the fourth non-limiting example game, and 
         FIG.  43    is a subroutine showing a specific non-limiting example of a jump display process performed in step S 410  shown in  FIG.  42   . 
     
    
    
     DETAILED DESCRIPTION OF NON-LIMITING EXAMPLE EMBODIMENTS 
     An information processing system according to this non-limiting example will now be described. The information processing system of this non-limiting example employs a game system  1  in a non-limiting example.  FIG.  1    is a diagram showing a non-limiting example of apparatuses included in the game system  1 . As shown in  FIG.  1   , the game system  1  includes a main body apparatus  2 , a left controller  3  and a right controller  4 , a ring-shaped extension apparatus  5 , and a belt-shaped extension apparatus  6 . 
     The main body apparatus  2  is a non-limiting example of an information processing apparatus, and functions as a game device main body in this non-limiting example. The left controller  3  and the right controller  4  are attachable to and detachable from the main body apparatus  2  (see  FIG.  1    and  FIG.  3   ). That is, the user can attach the left controller  3  and the right controller  4  to the main body apparatus  2 , and use them as a unified apparatus (see  FIG.  2   ). The user can also use the main body apparatus  2  and the left controller  3  and the right controller  4  separately from each other (see  FIG.  3   ). Note that the main body apparatus  2  and the controllers  3  and  4  may hereinafter be referred to collectively as a “game apparatus.” 
     The ring-shaped extension apparatus  5  is a non-limiting example of an extension apparatus that is used with the right controller  4 . The ring-shaped extension apparatus  5  is used with the right controller  4  attached thereto. The belt-shaped extension apparatus  6  is a non-limiting example of an extension apparatus that is used with the left controller  3 . The belt-shaped extension apparatus  6  is used with the left controller  3  attached thereto. Thus, in this non-limiting example, the user can use the controllers  3  and  4  while they are attached to the respective extension apparatuses (see  FIG.  12   ). Note that the ring-shaped extension apparatus  5  is not limited for use with the right controller  4 , but the left controller  3  may be attachable thereto. The belt-shaped extension apparatus  6  is not limited for use with the left controller  3 , but the right controller  4  may be attachable thereto. Note that as described below, the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6  function as an extension apparatus capable of extending or changing the respective functions or use forms of the right controller  4  and the left controller  3 , and may each be simply called a “peripheral apparatus.” 
       FIG.  2    is a diagram showing a non-limiting example of the state where the left controller  3  and the right controller  4  are attached to the main body apparatus  2 . As shown in  FIG.  2   , each of the left controller  3  and the right controller  4  is attached to and unified with the main body apparatus  2 . The main body apparatus  2  is an apparatus for performing various processes (e.g., game processing) in the game system  1 . The main body apparatus  2  includes a display  12 . Each of the left controller  3  and the right controller  4  is an apparatus including operation sections with which a user provides inputs. 
       FIG.  3    is a diagram showing a non-limiting example of the state where each of the left controller  3  and the right controller  4  is detached from the main body apparatus  2 . As shown in  FIGS.  2  and  3   , the left controller  3  and the right controller  4  are attachable to and detachable from the main body apparatus  2 . It should be noted that hereinafter, the left controller  3  and the right controller  4  will occasionally be referred to collectively as a “controller.” 
       FIG.  4    is six orthogonal views showing a non-limiting example of the main body apparatus  2 . As shown in  FIG.  4   , the main body apparatus  2  includes an approximately plate-shaped housing  11 . In this non-limiting example, a main surface (in other words, a surface on a front side, i.e., a surface on which the display  12  is provided) of the housing  11  has a generally rectangular shape. 
     It should be noted that the shape and the size of the housing  11  are optional. As an example, the housing  11  may be of a portable size. Further, the main body apparatus  2  alone or the unified apparatus obtained by attaching the left controller  3  and the right controller  4  to the main body apparatus  2  may function as a mobile apparatus. The main body apparatus  2  or the unified apparatus may function as a handheld apparatus or a portable apparatus. 
     As shown in  FIG.  4   , the main body apparatus  2  includes the display  12 , which is provided on the main surface of the housing  11 . The display  12  displays an image generated by the main body apparatus  2 . In this non-limiting example, the display  12  is a liquid crystal display device (LCD). The display  12 , however, may be a display device of any type. 
     In addition, the main body apparatus  2  includes a touch panel  13  on the screen of the display  12 . In this non-limiting example, the touch panel  13  allows multi-touch input (e.g., a capacitive touch panel). It should be noted that the touch panel  13  may be of any suitable type, e.g., it allows single-touch input (e.g., a resistive touch panel). 
     The main body apparatus  2  includes a speaker (i.e., a speaker  88  shown in  FIG.  7   ) inside the housing  11 . As shown in  FIG.  4   , speaker holes  11   a  and  11   b  are formed in the main surface of the housing  11 . The speaker  88  outputs sounds through the speaker holes  11   a  and  11   b.    
     The main body apparatus  2  also includes a left-side terminal  17  that enables wired communication between the main body apparatus  2  and the left controller  3 , and a right-side terminal  21  that enables wired communication between the main body apparatus  2  and the right controller  4 . 
     As shown in  FIG.  4   , the main body apparatus  2  includes a slot  23 . The slot  23  is provided on an upper side surface of the housing  11 . The slot  23  is so shaped as to allow a predetermined type of storage medium to be attached to the slot  23 . The predetermined type of storage medium is, for example, a dedicated storage medium (e.g., a dedicated memory card) for the game system  1  and an information processing apparatus of the same type as the game system  1 . The predetermined type of storage medium is used to store, for example, data (e.g., saved data of an application or the like) used by the main body apparatus  2  and/or a program (e.g., a program for an application or the like) executed by the main body apparatus  2 . Further, the main body apparatus  2  includes a power button  28 . 
     The main body apparatus  2  includes a lower-side terminal  27 . The lower-side terminal  27  allows the main body apparatus  2  to communicate with a cradle. In this non-limiting example, the lower-side terminal  27  is a USB connector (more specifically, a female connector). When the unified apparatus or the main body apparatus  2  alone is placed on the cradle, the game system  1  can display, on a stationary monitor, an image that is generated and output by the main body apparatus  2 . Also, in this non-limiting example, the cradle has the function of charging the unified apparatus or the main body apparatus  2  alone, being placed thereon. The cradle also functions as a hub device (specifically, a USB hub). 
       FIG.  5    is six orthogonal views showing a non-limiting example of the left controller  3 . As shown in  FIG.  5   , the left controller  3  includes a housing  31 . In this non-limiting example, the housing  31  has a vertically long shape, e.g., is shaped to be long in an up-down direction (i.e., a y-axis direction shown in  FIGS.  2  and  5   ). In the state where the left controller  3  is detached from the main body apparatus  2 , the left controller  3  can also be held in the orientation in which the left controller  3  is vertically long. The housing  31  has such a shape and a size that when held in the orientation in which the housing  31  is vertically long, the housing  31  can be held with one hand, particularly the left hand. Further, the left controller  3  can also be held in the orientation in which the left controller  3  is horizontally long. When held in the orientation in which the left controller  3  is horizontally long, the left controller  3  may be held with both hands. 
     The left controller  3  includes an analog stick  32 . As shown in  FIG.  5   , the analog stick  32  is provided on a main surface of the housing  31 . The analog stick  32  can be used as a direction input section with which a direction can be input. The user tilts the analog stick  32  and thereby can input a direction corresponding to the direction of the tilt (and input a magnitude corresponding to the angle of the tilt). It should be noted that the left controller  3  may include a directional pad, a slide stick that allows a slide input, or the like as the direction input section, instead of the analog stick. Further, in this non-limiting example, it is possible to provide an input by pressing the analog stick  32 . 
     The left controller  3  includes various operation buttons. The left controller  3  includes four operation buttons  33  to  36  (specifically, a right direction button  33 , a down direction button  34 , an up direction button  35 , and a left direction button  36 ) on the main surface of the housing  31 . Further, the left controller  3  includes a record button  37  and a “−” (minus) button  47 . The left controller  3  includes a first L-button  38  and a ZL-button  39  in an upper left portion of a side surface of the housing  31 . Further, the left controller  3  includes a second L-button  43  and a second R-button  44 , on the side surface of the housing  31  on which the left controller  3  is attached to the main body apparatus  2 . These operation buttons are used to give instructions depending on various programs (e.g., an OS program and an application program) executed by the main body apparatus  2 . 
     The left controller  3  also includes a terminal  42  that enables wired communication between the left controller  3  and the main body apparatus  2 . 
       FIG.  6    is six orthogonal views showing a non-limiting example of the right controller  4 . As shown in  FIG.  6   , the right controller  4  includes a housing  51 . In this non-limiting example, the housing  51  has a vertically long shape, e.g., is shaped to be long in the up-down direction. In the state where the right controller  4  is detached from the main body apparatus  2 , the right controller  4  can also be held in the orientation in which the right controller  4  is vertically long. The housing  51  has such a shape and a size that when held in the orientation in which the housing  51  is vertically long, the housing  51  can be held with one hand, particularly the right hand. Further, the right controller  4  can also be held in the orientation in which the right controller  4  is horizontally long. When held in the orientation in which the right controller  4  is horizontally long, the right controller  4  may be held with both hands. 
     Similarly to the left controller  3 , the right controller  4  includes an analog stick  52  as a direction input section. In this non-limiting example, the analog stick  52  has the same configuration as that of the analog stick  32  of the left controller  3 . Further, the right controller  4  may include a directional pad, a slide stick that allows a slide input, or the like, instead of the analog stick. Further, similarly to the left controller  3 , the right controller  4  includes four operation buttons  53  to  56  (specifically, an A-button  53 , a B-button  54 , an X-button  55 , and a Y-button  56 ) on a main surface of the housing  51 . Further, the right controller  4  includes a “+” (plus) button  57  and a home button  58 . Further, the right controller  4  includes a first R-button  60  and a ZR-button  61  in an upper right portion of a side surface of the housing  51 . Further, similarly to the left controller  3 , the right controller  4  includes a second L-button  65  and a second R-button  66 . 
     Further, a window portion  68  is provided on a lower side surface of the housing  51 . Although the details will be described later, the right controller  4  includes an infrared image capturing section  123  and an infrared light-emitting section  124 , which are placed within the housing  51 . The infrared image capturing section  123  captures a portion around the right controller  4  through the window portion  68  such that a down direction of the right controller  4  (a negative y-axis direction shown in  FIG.  6   ) is the image capturing direction. The infrared light-emitting section  124  emits infrared light through the window portion  68  to an image capturing target to be captured by the infrared image capturing section  123  such that a predetermined range about the down direction of the right controller  4  (the negative y-axis direction shown in  FIG.  6   ) is the emission range. The window portion  68  is used to protect a lens of a camera of the infrared image capturing section  123 , a light emitter of the infrared light-emitting section  124 , and the like and composed of a material (e.g., a transparent material) that transmits light of a wavelength sensed by the camera and light emitted from the light emitter. It should be noted that the window portion  68  may be a hole formed in the housing  51 . It should be noted that in this non-limiting example, the infrared image capturing section  123  itself includes a filter member for inhibiting the transmission of light of a wavelength other than light sensed by the camera (infrared light in this non-limiting example). In another non-limiting example, the window portion  68  may have the function of a filter. 
     Further, the right controller  4  includes a terminal  64  for allowing the right controller  4  to perform wired communication with the main body apparatus  2 . 
       FIG.  7    is a block diagram showing a non-limiting example of an internal configuration of the main body apparatus  2 . The main body apparatus  2  includes components  81  to  91 ,  97 , and  98  shown in  FIG.  7    in addition to the components shown in  FIG.  4   . Some of the components  81  to  98  may be implemented as electronic parts on an electronic circuit board, which is contained in the housing  11 . 
     The main body apparatus  2  includes a processor  81 . The processor  81  is an information processor for executing various types of information processing to be executed by the main body apparatus  2 . For example, the CPU  81  may include only a central processing unit (CPU), or may be a system-on-a-chip (SoC) having a plurality of functions such as a CPU function and a graphics processing unit (GPU) function. The processor  81  executes an information processing program (e.g., a game program) stored in a storage section (specifically, an internal storage medium such as a flash memory  84 , an external storage medium that is attached to the slot  23 , or the like), thereby executing the various types of information processing. 
     The main body apparatus  2  includes a flash memory  84  and a dynamic random access memory (DRAM)  85  as examples of internal storage media built in itself. The flash memory  84  and the DRAM  85  are connected to the CPU  81 . The flash memory  84  is mainly used to store various data (or programs) to be saved in the main body apparatus  2 . The DRAM  85  is used to temporarily store various data used in information processing. 
     The main body apparatus  2  includes a slot interface (hereinafter abbreviated to “I/F”)  91 . The slot I/F  91  is connected to the processor  81 . The slot I/F  91  is connected to the slot  23 , and reads and writes data from and to a predetermined type of storage medium (e.g., a dedicated memory card) attached to the slot  23 , in accordance with commands from the processor  81 . 
     The processor  81  reads and writes, as appropriate, data from and to the flash memory  84 , the DRAM  85 , and each of the above storage media, thereby executing the above information processing. 
     The main body apparatus  2  includes a network communication section  82 . The network communication section  82  is connected to the processor  81 . The network communication section  82  communicates (specifically, through wireless communication) with an external apparatus via a network. In this non-limiting example, as a first communication form, the network communication section  82  connects to a wireless LAN and communicates with an external apparatus, using a method compliant with the Wi-Fi standard. Further, as a second communication form, the network communication section  82  wirelessly communicates with another main body apparatus  2  of the same type, using a predetermined communication method (e.g., communication based on a particular protocol or infrared light communication). It should be noted that the wireless communication in the above second communication form achieves the function of allowing so-called “local communication,” in which the main body apparatus  2  can wirelessly communicate with another main body apparatus  2  located in a closed local network area, and the plurality of main body apparatuses  2  directly communicate with each other to exchange data. 
     The main body apparatus  2  includes a controller communication section  83 . The controller communication section  83  is connected to the processor  81 . The controller communication section  83  wirelessly communicates with the left controller  3  and/or the right controller  4 . The main body apparatus  2  may communicate with the left and right controllers  3  and  4  using any suitable communication method. In this non-limiting example, the controller communication section  83  performs communication with the left and right controllers  3  and  4  in accordance with the Bluetooth (registered trademark) standard. 
     The processor  81  is connected to the left-side terminal  17 , the right-side terminal  21 , and the lower-side terminal  27 . When performing wired communication with the left controller  3 , the processor  81  transmits data to the left controller  3  via the left-side terminal  17  and also receives operation data from the left controller  3  via the left-side terminal  17 . Further, when performing wired communication with the right controller  4 , the processor  81  transmits data to the right controller  4  via the right-side terminal  21  and also receives operation data from the right controller  4  via the right-side terminal  21 . Further, when communicating with the cradle, the processor  81  transmits data to the cradle via the lower-side terminal  27 . As described above, in this non-limiting example, the main body apparatus  2  can perform both wired communication and wireless communication with each of the left and right controllers  3  and  4 . Further, when the unified apparatus obtained by attaching the left and right controllers  3  and  4  to the main body apparatus  2  or the main body apparatus  2  alone is attached to the cradle, the main body apparatus  2  can output data (e.g., image data or sound data) to a stationary monitor or the like via the cradle. 
     Here, the main body apparatus  2  can communicate with a plurality of left controllers  3  simultaneously (or in parallel). Further, the main body apparatus  2  can communicate with a plurality of right controllers  4  simultaneously (or in parallel). Thus, a plurality of users can simultaneously provide inputs to the main body apparatus  2 , each using a set of left and right controllers  3  and  4 . In a non-limiting example, a first user can provide an input to the main body apparatus  2  using a first set of left and right controllers  3  and  4 , and at the same time, a second user can provide an input to the main body apparatus  2  using a second set of left and right controllers  3  and  4 . 
     The main body apparatus  2  includes a touch panel controller  86  that is a circuit for controlling the touch panel  13 . The touch panel controller  86  is connected between the touch panel  13  and the processor  81 . Based on a signal from the touch panel  13 , the touch panel controller  86  generates, for example, data indicating a position where a touch input has been performed. Then, the touch panel controller  86  outputs the data to the processor  81 . 
     Further, the display  12  is connected to the processor  81 . The processor  81  displays, on the display  12 , a generated image (e.g., an image generated by executing the above information processing) and/or an externally obtained image. 
     The main body apparatus  2  includes a codec circuit  87  and speakers (specifically, a left speaker and a right speaker)  88 . The codec circuit  87  is connected to the speakers  88  and an audio input/output terminal  25  and also connected to the processor  81 . The codec circuit  87  is for controlling the input and output of audio data to and from the speakers  88  and the sound input/output terminal  25 . 
     Further, the main body apparatus  2  includes an acceleration sensor  89 . In this non-limiting example, the acceleration sensor  89  detects the magnitudes of accelerations along predetermined three axial (e.g., x-, y-, and z-axes shown in  FIG.  1   ) directions. It should be noted that the acceleration sensor  89  may detect an acceleration along one axial direction or accelerations along two axial directions. 
     Further, the main body apparatus  2  includes an angular velocity sensor  90 . In this non-limiting example, the angular velocity sensor  90  detects angular velocities about predetermined three axes (e.g., the x-, y-, and z-axes shown in  FIG.  2   ). It should be noted that the angular velocity sensor  90  may detect an angular velocity about one axis or angular velocities about two axes. 
     The acceleration sensor  89  and the angular velocity sensor  90  are connected to the processor  81 . The detection results of the acceleration sensor  89  and the angular velocity sensor  90  are output to the processor  81 . Based on the detection results of the acceleration sensor  89  and the angular velocity sensor  90 , the processor  81  can calculate information about a motion and/or orientation of the main body apparatus  2 . 
     The main body apparatus  2  includes a power control section  97  and a battery  98 . The power control section  97  is connected to the battery  98  and the processor  81 . Further, although not shown, the power control section  97  is connected to components of the main body apparatus  2  (specifically, components that receive power supplied from the battery  98 , the left-side terminal  17 , and the right-side terminal  21 ). Based on a command from the processor  81 , the power control section  97  controls the supply of power from the battery  98  to each of the above components. 
     Further, the battery  98  is connected to the lower-side terminal  27 . When an external charging device (e.g., the cradle) is connected to the lower-side terminal  27 , and power is supplied to the main body apparatus  2  via the lower-side terminal  27 , the battery  98  is charged with the supplied power. 
       FIG.  8    is a block diagram showing examples of the internal configurations of the main body apparatus  2 , the left controller  3 , and the right controller  4 . It should be noted that the details of the internal configuration of the main body apparatus  2  are shown in  FIG.  7    and therefore are omitted in  FIG.  8   . 
     The left controller  3  includes a communication control section  101 , which communicates with the main body apparatus  2 . As shown in  FIG.  8   , a communication control section  101  is connected to components including the terminal  42 . In this non-limiting example, the communication control section  101  can communicate with the main body apparatus  2  through both wired communication via the terminal  42  and wireless communication not via the terminal  42 . The communication control section  101  controls the method for communication performed by the left controller  3  with the main body apparatus  2 . That is, when the left controller  3  is attached to the main body apparatus  2 , the communication control section  101  communicates with the main body apparatus  2  via the terminal  42 . Further, when the left controller  3  is detached from the main body apparatus  2 , the communication control section  101  wirelessly communicates with the main body apparatus  2  (specifically, the controller communication section  83 ). The wireless communication between the communication control section  101  and the controller communication section  83  is performed in accordance with the Bluetooth (registered trademark) standard, for example. 
     Further, the left controller  3  includes a memory  102  such as a flash memory. The communication control section  101  includes, for example, a microcomputer (or a microprocessor) and executes firmware stored in the memory  102 , thereby performing various processes. 
     The left controller  3  includes buttons  103  (specifically, the buttons  33  to  39 ,  43 ,  44 , and  47 ). Further, the left controller  3  includes the analog stick (“stick” in  FIG.  8   )  32 . Each of the buttons  103  and the analog stick  32  outputs information regarding an operation performed on itself to the communication control section  101  repeatedly at appropriate timing. 
     The left controller  3  includes inertial sensors. Specifically, the left controller  3  includes an acceleration sensor  104 . Further, the left controller  3  includes an angular velocity sensor  105 . In this non-limiting example, the acceleration sensor  104  detects the magnitudes of accelerations along predetermined three axial (e.g., xyz axes shown in  FIG.  5   ) directions. It should be noted that the acceleration sensor  104  may detect an acceleration along one axial direction or accelerations along two axial directions. In this non-limiting example, an angular velocity sensor  105  detects angular velocities about predetermined three axes (e.g., the xyz axes shown in  FIG.  5   ). It should be noted that the angular velocity sensor  105  may detect an angular velocity about one axis or angular velocities about two axes. Each of the acceleration sensor  104  and the angular velocity sensor  105  is connected to the communication control section  101 . Then, the detection results of the acceleration sensor  104  and the angular velocity sensor  105  are output to the communication control section  101  repeatedly at appropriate timing. Note that the inertial sensor (e.g., the acceleration sensor  104  and the angular velocity sensor  105 ) included in the left controller  3  corresponds to a non-limiting example of a motion sensor of a second input apparatus. 
     The communication control section  101  acquires information regarding an input (specifically, information regarding an operation or the detection result of the sensor) from each of input sections (specifically, the buttons  103 , the analog stick  32 , and the sensors  104  and  105 ). The communication control section  101  transmits operation data including the acquired information (or information obtained by performing predetermined processing on the acquired information) to the main body apparatus  2 . It should be noted that the operation data is transmitted repeatedly, once every predetermined time. It should be noted that the interval at which the information regarding an input is transmitted from each of the input sections to the main body apparatus  2  may or may not be the same. 
     The above operation data is transmitted to the main body apparatus  2 , whereby the main body apparatus  2  can obtain inputs provided to the left controller  3 . That is, the main body apparatus  2  can determine operations on the buttons  103  and the analog stick  32  based on the operation data. Further, the main body apparatus  2  can calculate information regarding the motion and/or the orientation of the left controller  3  based on the operation data (specifically, the detection results of the acceleration sensor  104  and the angular velocity sensor  105 ). 
     The left controller  3  includes a vibrator  107  for giving notification to the user by a vibration. In this non-limiting example, the vibrator  107  is controlled by a command from the main body apparatus  2 . That is, if receiving the above command from the main body apparatus  2 , the communication control section  101  drives the vibrator  107  in accordance with the received command. Here, the left controller  3  includes a codec section  106 . If receiving the above command, the communication control section  101  outputs a control signal corresponding to the command to the codec section  106 . The codec section  106  generates a driving signal for driving the vibrator  107  from the control signal from the communication control section  101  and outputs the driving signal to the vibrator  107 . Consequently, the vibrator  107  operates. 
     More specifically, the vibrator  107  is a linear vibration motor. Unlike a regular motor that rotationally moves, the linear vibration motor is driven in a predetermined direction in accordance with an input voltage and therefore can be vibrated at an amplitude and a frequency corresponding to the waveform of the input voltage. In this non-limiting example, a vibration control signal transmitted from the main body apparatus  2  to the left controller  3  may be a digital signal representing the frequency and the amplitude every unit of time. In another non-limiting example, the main body apparatus  2  may transmit information indicating the waveform itself. The transmission of only the amplitude and the frequency, however, enables a reduction in the amount of communication data. Additionally, to further reduce the amount of data, only the differences between the numerical values of the amplitude and the frequency at that time and the previous values may be transmitted, instead of the numerical values. In this case, the codec section  106  converts a digital signal indicating the values of the amplitude and the frequency acquired from the communication control section  101  into the waveform of an analog voltage and inputs a voltage in accordance with the resulting waveform, thereby driving the vibrator  107 . Thus, the main body apparatus  2  changes the amplitude and the frequency to be transmitted every unit of time and thereby can control the amplitude and the frequency at which the vibrator  107  is to be vibrated at that time. It should be noted that not only a single amplitude and a single frequency, but also two or more amplitudes and two or more frequencies may be transmitted from the main body apparatus  2  to the left controller  3 . In this case, the codec section  106  combines waveforms indicated by the plurality of received amplitudes and frequencies and thereby can generate the waveform of a voltage for controlling the vibrator  107 . 
     The left controller  3  includes a power supply section  108 . In this non-limiting example, the power supply section  108  includes a battery and a power control circuit. Although not shown in  FIG.  8   , the power control circuit is connected to the battery and also connected to components of the left controller  3  (specifically, components that receive power supplied from the battery). 
     As shown in  FIG.  8   , the right controller  4  includes a communication control section  111 , which communicates with the main body apparatus  2 . Further, the right controller  4  includes a memory  112 , which is connected to the communication control section  111 . The communication control section  111  is connected to components including the terminal  64 . The communication control section  111  and the memory  112  have functions similar to those of the communication control section  101  and the memory  102 , respectively, of the left controller  3 . Thus, a communication control section  111  can communicate with the main body apparatus  2  through both wired communication via the terminal  64  and wireless communication not via the terminal  64  (specifically, communication compliant with the Bluetooth (registered trademark) standard). The communication control section  111  controls the method for communication performed by the right controller  4  with the main body apparatus  2 . 
     The right controller  4  includes input sections similar to the input sections of the left controller  3 . Specifically, the right controller  4  includes buttons  113 , the analog stick  52 , and inertial sensors (an acceleration sensor  114  and an angular velocity sensor  115 ). These input sections have functions similar to those of the input sections of the left controller  3  and operate similarly to the input sections of the left controller  3 . It should be noted that the inertial sensors (e.g., the acceleration sensor  114  and the angular velocity sensor  115 ) correspond to a non-limiting example of a motion sensor of a first input apparatus. 
     Further, the right controller  4  includes a vibrator  117  and a codec section  116 . The vibrator  117  and the codec section  116  operate similarly to the vibrator  107  and the codec section  106 , respectively, of the left controller  3 . That is, in accordance with a command from the main body apparatus  2 , the communication control section  111  causes the vibrator  117  to operate, using the codec section  116 . 
     Further, the right controller  4  includes the infrared image capturing section  123 . The infrared image capturing section  123  includes an infrared camera for capturing a portion around the right controller  4 . As an example, the main body apparatus  2  and/or the right controller  4  calculate information of a captured image (e.g., information related to the luminance of a plurality of blocks into which at least the entirety of a partial area of a captured image is divided or the like), and based on the calculated information, determine a change in the portion around the right controller  4 . Further, the infrared image capturing section  123  may capture an image using ambient light, but in this non-limiting example, includes the infrared light-emitting section  124 , which emits infrared light. The infrared light-emitting section  124  emits infrared light, for example, in synchronization with the timing when the infrared camera captures an image. Then, the infrared light emitted from the infrared light-emitting section  124  is reflected by an image capturing target, and the infrared camera receives the reflected infrared light, thereby acquiring an image of the infrared light. This enables the infrared image capturing section  123  to obtain a clearer infrared light image. It should be noted that the infrared image capturing section  123  and the infrared light-emitting section  124  may be provided as different devices in the right controller  4 , or may be provided as a single device in the same package in the right controller  4 . Further, in this non-limiting example, the infrared image capturing section  123  including an infrared camera is used. In another non-limiting example, a visible light camera (a camera using a visible light image sensor) may be used as image capturing means, instead of the infrared camera. 
     The right controller  4  includes a processing section  121 . The processing section  121  is connected to the communication control section  111 . Further, the processing section  121  is connected to the infrared image capturing section  123  and the infrared light-emitting section  124 . 
     Further, the processing section  121  includes a CPU, a memory, and the like. Based on a predetermined program (e.g., an application program for performing image processing and various calculations) stored in a storage device (e.g., a non-volatile memory or the like) (not shown) included in the right controller  4 , and in accordance with a command from the main body apparatus  2 , the processing section  121  performs the process of managing the infrared image capturing section  123 . For example, the processing section  121  causes the infrared image capturing section  123  to perform an image capturing operation. Further, the processing section  121  acquires and/or calculates information based on an image capturing result (information of a captured image, information calculated from this information, or the like) and transmits the information to the main body apparatus  2  via the communication control section  111 . Further, in accordance with a command from the main body apparatus  2 , the processing section  121  performs the process of managing the infrared light-emitting section  124 . For example, in accordance with a command from the main body apparatus  2 , the processing section  121  controls the light emission of the infrared light-emitting section  124 . It should be noted that a memory used by the processing section  121  to perform processing may be provided in the processing section  121  or may be the memory  112 . 
     The right controller  4  includes a power supply section  118 . The power supply section  118  has a function similar to that of the power supply section  108  of the left controller  3  and operates similarly to the power supply section  108 . 
       FIG.  9    is a diagram showing a non-limiting example of a ring-shaped extension apparatus. It should be noted that  FIG.  9    shows the ring-shaped extension apparatus  5  with the right controller  4  attached thereof. In this non-limiting example, the ring-shaped extension apparatus  5  is an extension apparatus to which the right controller  4  can be attached. Although the details will be described later, the user performs a novel operation of applying a force to, and deforming, the ring-shaped extension apparatus  5  in this non-limiting example. The user can operate the ring-shaped extension apparatus  5  by performing a fitness exercise operation using the ring-shaped extension apparatus  5  as if the user were doing an exercise, for example. It should be noted that the ring-shaped extension apparatus  5  corresponds to a non-limiting example of the first input apparatus. 
     As shown in  FIG.  9   , the ring-shaped extension apparatus  5  includes a ring-shaped portion  201  and a main portion  202 . The ring-shaped portion  201  has a ring shape. Note that in this non-limiting example, the ring-shaped portion  201  includes an elastic member and a base portion to be described below, which together form a ring shape. In this non-limiting example, the ring-shaped portion  201  has a circular ring shape. Note that in other non-limiting examples, the ring-shaped portion  201  may be of any suitable shape, e.g., an elliptical ring shape. 
     The main portion  202  is provided on the ring-shaped portion  201 . The main portion  202  has a rail portion (not shown). The rail portion is a non-limiting example of an attachment portion to which the right controller  4  can be attached. In this non-limiting example, the rail portion is slidably engaged with a slider  62  (see  FIG.  6   ) of the right controller  4 . When the slider  62  is inserted into a rail member in a predetermined linear direction (i.e., a slide direction), the rail member is engaged with the slider  62  while the slider  62  is allowed to be slid in the linear direction relative to the rail member. Note that the rail portion is similar to that of the main body apparatus  2  in that the rail portion can be slidably engaged with the slider of the controller. Therefore, the rail portion may have a structure similar to that of the rail portion of the main body apparatus  2 . 
     In this non-limiting example, the right controller  4  includes a latch portion  63  (see  FIG.  6   ). The latch portion  63  is provided so as to protrude sideways (i.e., the z-axis positive direction shown in  FIG.  6   ) from the slider  62 . While the latch portion  63  is allowed to move into the slider  62 , the latch portion  63  is urged (e.g., by means of a spring) into the position described above in which the latch portion  63  is protruding sideways. The rail portion is provided with a notch. In a state where the slider  62  is inserted to the far end of the rail portion, the latch portion  63  snaps into the notch. With the slider  62  inserted to the far end of the rail portion  211 , the latch portion  63  snaps into the notch  219 . As the latch portion  63  engages with the notch while the rail portion is in engagement with the slider  62 , the right controller  4  is attached to the main portion  202 . 
     Note that the right controller  4  includes the release button  69  that can be pressed (see  FIG.  6   ). In response to the release button  69  being pressed, the latch portion  63  moves into the slider  62 , achieving the state where the latch portion  63  no longer (or substantially no longer) protrudes relative to the slider  62 . Therefore, when the release button  69  is pressed in the state where the right controller  4  is attached to the main portion  202  of the ring-shaped extension apparatus  5 , the latch portion  63  is no longer (or is substantially no longer) in engagement with the notch. Thus, in the state where the right controller  4  is attached to the main portion  202  of the ring-shaped extension apparatus  5 , the user can easily remove the right controller  4  from the ring-shaped extension apparatus  5  by pressing the release button  69 . 
     As shown in  FIG.  9   , the ring-shaped extension apparatus  5  has grip covers  203  and  204 . The grip covers  203  and  204  are parts that are held by the user. In this non-limiting example, the grip covers  203  and  204  are removable from the ring-shaped portion  201 . In this non-limiting example, the left grip cover  203  is provided on the left grip portion near the left end of the ring-shaped portion  201 , and the right grip cover  204  is provided on the right grip portion near the right end of the ring-shaped portion  201 . Note that there is no limitation on the number of grip portions, and the grip portions may be provided at three or more locations, or at only one location, depending on the operation method or methods contemplated. Depending on the content of the game (or the content of the fitness exercise operation to be performed by the user in the game), only a particular one or particular ones of a plurality of grip portions may be held by one hand or both hands. 
       FIG.  10    is a block diagram showing a non-limiting electrical connection relationship between components included in the ring-shaped extension apparatus  5 . As shown in  FIG.  10   , the ring-shaped extension apparatus  5  includes a strain detector  211 . The strain detector  211  is a non-limiting example of a detector that detects when the ring-shaped portion  201  is deformed. In this non-limiting example, the strain detector  211  includes a strain gauge. The strain detector  211  outputs a signal indicating a strain of a base portion that depends on a deformation of an elastic member to be described below (in other words, a signal indicating the magnitude and direction of deformation of the elastic member). 
     Here, in this non-limiting example, the ring-shaped portion  201  has an elastically deformable elastic portion and a base portion. The base portion holds opposite end portions of the elastic member so that the base portion and the elastic member together form a ring. Note that the base portion is provided inside the main portion  202 , and therefore, is not shown in  FIG.  9   . The base portion is formed of a material having a stiffness higher than that of the elastic member. For example, the elastic member is formed of a resin (specifically, a fiber reinforced plastic (FRP)), and the base portion is formed of a metal. The strain gauge, which is provided on the base portion, detects a strain of the base portion. When the ring-shaped portion  201  is deformed from a steady state thereof, a strain occurs in the base portion due to the deformation. The strain of the base portion is detected by the strain gauge. Based on the detected strain, a direction (i.e., a direction in which the two grip covers  203  and  204  move toward each other or away from each other) and amount of deformation of the ring-shaped portion  201  can be calculated. As used herein, the “steady state” with respect to the ring-shaped portion  201 , in which the elastic member is shaped into a ring so that the base portion and the elastic member together form a ring, indicates that a force that could deform the ring shape of the elastic member is not applied externally (e.g., from the user) to the ring-shaped portion  201  with the base portion holding the opposite end portions of the elastic member. As used herein, the term “deformed state” with respect to the ring-shaped portion  201  indicates a state that the ring-shaped portion  201  is deformed from the steady state when a force is externally applied thereto. The strain gauge detects a strain that occurs when the ring-shaped portion  201  is deformed from the ring shape, where the initial value is the strain value of the ring shape. 
     Note that in another non-limiting example, the strain detector  211  includes any suitable sensor that can detect when the ring-shaped portion  201  is deformed from the steady state, instead of the strain gauge. For example, the detector  211  may include a pressure sensor that can detect an applied pressure when the ring-shaped portion  201  is deformed, or a flex sensor that can detect the amount of bending of the ring-shaped portion  201 . 
     The ring-shaped extension apparatus  5  includes a signal conversion section  212 . In this non-limiting example, the signal conversion section  212  includes an amplifier and an A/D converter. The signal conversion section  212  is electrically connected to the strain detector  211 , and amplifies an output signal from the strain detector  211  by the amplifier and performs an A/D conversion by the A/D converter. The signal conversion section  212  outputs a digital signal indicating a strain value detected by the strain detector  211 . Note that in another non-limiting example, the signal conversion section  212  may not include an A/D converter, and a processing section  213  to be described below may include an A/D converter. 
     The ring-shaped extension apparatus  5  includes a processing section  213 . The processing section  213  is a processing circuit including a processor and a memory, and is, for example, a microcontroller unit (MCU). The processing section  213  is electrically connected to the signal conversion section  212 , and receives an output signal from the signal conversion section  212 . The ring-shaped extension apparatus  5  includes a terminal  214 . The terminal  214  is electrically connected to the processing section  213 . When the right controller  4  is attached to the ring-shaped extension apparatus  5 , the processing section  213  sends information (in other words, ring operation data to be described below) indicating a strain value indicated by an output signal from the signal conversion section  212  to the right controller  4  via the terminal  214 . 
     The ring-shaped extension apparatus  5  includes a power conversion section  215 . The power conversion section  215  is electrically connected to the above elements  211 - 214 . The power conversion section  215  supplies external power received via the terminal  214  (i.e., power supplied from the right controller  4 ) to the elements  211 - 214 . The power conversion section  215  may, for example, adjust the voltage of the received power before supplying the power to the elements  211 - 214 . 
     Note that the “data regarding the detection result of the strain detector” that is transmitted by the ring-shaped extension apparatus  5  to another device may be data representing the detection result (in this non-limiting example, the output signal from the strain detector  211  representing the strain of the base portion) itself, or may be data that is obtained by performing some processes on the detection result (e.g., data format conversion and/or an arithmetic process on the strain value, etc.). For example, the processing section  213  may perform a process of calculating the amount of deformation of the elastic member based on the strain value, which is the detection result, and the “data regarding the detection result of the strain detector” may be data that represents the amount of deformation. 
     Note that in other non-limiting examples, the ring-shaped extension apparatus  5  may include a battery and may operate by using power from the battery. The battery of the ring-shaped extension apparatus  5  may be a rechargeable battery that can be charged by power supplied from the right controller  4 . 
       FIG.  11    is a diagram showing a non-limiting example of a belt-shaped extension apparatus. The belt-shaped extension apparatus  6  is fastened to a leg of the user with the left controller  3  attached to the belt-shaped extension apparatus  6  (see  FIG.  12   ). As shown in  FIG.  11   , the belt-shaped extension apparatus  6  includes an accommodating portion  301  and a belt portion  302 . The accommodating portion  301  has a flat shape and is capable of accommodating the left controller  3  therein. Specifically, the accommodating portion  301  includes a pocket portion  303 . The pocket portion  303  is formed in a bag shape that is sized so that the left controller  3  can be accommodated therein. In this non-limiting example, as the left controller  3  is accommodated in the accommodating portion  301 , the left controller  3  is attached to the belt-shaped extension apparatus  6 . Note that in other non-limiting examples, there is no limitation on the configuration for attaching the left controller  3  to the belt-shaped extension apparatus  6 . Note that the belt-shaped extension apparatus  6  corresponds to a non-limiting example of the second input apparatus. 
     The accommodating portion  301  includes a through hole  304  on one side of the pocket portion  303 . The belt portion  302  is provided on one side of the pocket portion  303  of the accommodating portion  301 , i.e., on the opposite side from the through hole  304  with respect to the pocket portion  303 . The belt portion  302  has a band shape, and one end thereof is secured to the accommodating portion  301 . In this non-limiting example, the belt portion  302  is made of a flexible material (e.g., a woven rubber). 
     A first touch fastener  305  and a second touch fastener  306  are provided on the surface of the belt portion  302  on the same side as the pocket portion  303  is provided on the accommodating portion  301 . The first touch fastener  305  is provided near the end portion of the belt portion  302  that is on the opposite side from the other end portion that is secured to the accommodating portion  301 . The second touch fastener  306  is provided on the same surface as the first touch fastener  305  and on the side that is closer to the accommodating portion  301  than the first touch fastener  305 . The first touch fastener  305  and the second touch fastener  306  can be attached to and detached from each other. For example, the first touch fastener  305  may be a hook-surface touch fastener, and the second touch fastener  306  is a loop-surface touch fastener. 
     When fastening the belt-shaped extension apparatus  6 , the user passes the belt portion  302  through the through hole  304  with the belt portion  302  wound around a leg, and the user fastens together the first touch fastener  305  and the second touch fastener  306 . Thus, the user can fasten the belt-shaped extension apparatus  6 , with the left controller  3  attached thereto, to a leg (see  FIG.  12   ). 
       FIG.  12    is a diagram showing how the user uses the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6 . As shown in  FIG.  12   , the user can play a game using the two extension apparatuses  5  and  6  in addition to the game apparatus (i.e., the main body apparatus  2  and the controllers  3  and  4 ). For example, the user can use a set of the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6 . 
     For example, as shown in  FIG.  12   , the user holds, with both hands, the ring-shaped extension apparatus  5  with the right controller  4  attached thereto, and fastens, to a leg, the belt-shaped extension apparatus  6  with the left controller attached thereto. In this case, the user can play a game by performing an operation on the ring-shaped extension apparatus  5  (e.g., an operation of bending the ring-shaped extension apparatus  5  and an operation of moving the ring-shaped extension apparatus  5 ), and an operation of moving the leg to which the belt-shaped extension apparatus  6  is fastened. 
     Note that  FIG.  12    illustrates the user&#39;s action of bending the ring-shaped extension apparatus  5  while holding the grip covers  203  and  204 . By performing such an action, the user can perform a fitness exercise action for exercising both arms as a gaming operation. Note that the user can perform various actions on the ring-shaped extension apparatus  5  to perform gaming operations. For example, the user holds one of the grip covers with both hands, and performs an action of bending the ring-shaped extension apparatus  5  with the other grip cover in contact with the abdomen. By this action, the user can perform a fitness exercise action for exercising arm muscles and abdominal muscles as a gaming operation. The user can also perform an action of bending the ring-shaped extension apparatus  5  with the ring-shaped extension apparatus  5  between both legs, particularly the grip covers  203  and  204  being in contact with both inner thighs. By this action, the user can perform a fitness exercise action of exercising leg muscles as a gaming operation. 
     Where the game process is executed on the main body apparatus  2 , the right controller  4  receives the ring operation data from the ring-shaped extension apparatus  5 . The ring operation data includes information that represents the strain value. Specifically, the processing section  213  of the ring-shaped extension apparatus  5  transmits the ring operation data to the right controller  4  through the terminal  214 . For example, the processing section  213  repeatedly transmits the ring operation data at the rate of once per a predetermined amount of time. 
     In such a case, the communication control section  111  of the right controller  4  transmits the ring operation data, which has been received from the ring-shaped extension apparatus  5  through the terminal  64 , to the main body apparatus  2 . The communication control section  111  transmits, to the main body apparatus  2 , the right controller operation data including information obtained from the input sections included in the right controller  4  (specifically, the buttons  113 , the analog stick  52  and the sensors  114  and  115 ). Note that in the state that the right controller is attached to the ring-shaped extension apparatus  5 , the communication from the right controller  4  to the main body apparatus  2  is done by wireless communication. The communication control section  111  may transmit the right controller operation data and the ring operation data together with each other to the main body apparatus  2 , or may transmit the data separately to the main body apparatus  2 . The communication control section  111  may transmit the received ring operation data to the main body apparatus  2  as it is, or may perform some processes (e.g., data format conversion and/or an arithmetic process on the strain value, etc.) on the received ring operation data and transmit the processed data to the main body apparatus  2 . 
     On the other hand, where the game process is executed on the main body apparatus  2 , the communication control section  101  of the left controller  3  transmits the left controller operation data including information obtained from the input sections included in the left controller  3  (specifically, the buttons  103 , the analog stick  32  and the sensors  104  and  105 ) to the main body apparatus  2 . When the left controller  3  is attached to the belt-shaped extension apparatus  6 , the communication from the left controller  3  to the main body apparatus  2  is done by wireless communication. 
     First Non-Limiting Example Game 
     Next, before describing a specific process in a first non-limiting example game performed by the main body apparatus  2 , the first non-limiting example game performed in the main body apparatus  2  will be outlined with reference to  FIGS.  13 - 15   . Note that  FIG.  13    is a diagram showing a non-limiting example of how, in the first non-limiting example game, the user operates the ring-shaped extension apparatus  5 .  FIG.  14    is a diagram showing a first non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the first non-limiting example game.  FIG.  15    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the first non-limiting example game. 
     As shown in  FIG.  13   , in the first non-limiting example game, while holding both of the grip covers  203  and  204  of the ring-shaped extension apparatus  5  with both hands, the user performs an operation of deforming the ring-shaped extension apparatus  5  with both hands so that the two grip covers  203  and  204  of the ring-shaped extension apparatus  5  move toward each other, and an operation of moving both knees so that the knees are bent and extended. By such an operation of bending and extending the knees, the belt-shaped extension apparatus  6  fastened to the user&#39;s left thigh is also moved. Here, when the user bends and extends both knees while deforming the ring-shaped extension apparatus  5  so that the two grip covers  203  and  204  move toward each other, the user performs a gaming operation of performing an action of moving the ring-shaped extension apparatus  5  vertically, i.e., upward and downward while applying a force to the ring-shaped extension apparatus  5  held with both hands. 
     As described above, in the game system  1  of this non-limiting example, the left controller  3  and the right controller  4  are removable from the main body apparatus  2 . In addition, as shown in  FIGS.  14  and  15   , when the main body apparatus  2  alone is attached to the cradle  8 , an image (and sound) can be output from the stationary monitor  9 . The game system  1  will now be described, assuming the situation that the left controller  3  and the right controller  4  are removed from the main body apparatus  2 , the main body apparatus  2  alone is attached to the cradle  8 , and an image (and sound) is output from the stationary monitor  9  connected to the cradle  8 . In a non-limiting example, the user performs a gaming operation using the right controller  4  attached to the ring-shaped extension apparatus  5  and the left controller attached to the belt-shaped extension apparatus  6 . In a non-limiting example of a game process in the first non-limiting example game, used is a process of causing movement objects OBJ 2   a  and OBJ 2   b  displayed on the stationary monitor  9  to move vertically and horizontally according to the user&#39;s operation so that a target object OBJ 1  rotating in the virtual game space is deformed. Although in a non-limiting example shown in  FIGS.  14  and  15   , the target object OBJ 1  is a cylindrical object, the target object OBJ 1  may be a rotating object having other shapes or a non-rotating object having other shapes. 
     For example, in  FIG.  14   , the target object OBJ 1  is disposed in the virtual game space. A pair of the movement objects OBJ 2   a  and OBJ 2   b  are disposed on the left and right sides of the target object OBJ 1 . By moving the movement objects OBJ 2   a  and OBJ 2   b  into the rotating target object OBJ 1  with the movement objects OBJ 2   a  and OBJ 2   b  kept in contact with the target object OBJ 1  as if the movement objects OBJ 2   a  and OBJ 2   b  were pushed into the target object OBJ 1 , the target object OBJ 1  can be deformed in any suitable form. The movement objects OBJ 2   a  and OBJ 2   b  can be moved vertically along the surface of the target object OBJ 1  according to the user&#39;s operation of bending and extending the knees. In addition, the movement objects OBJ 2   a  and OBJ 2   b  can be moved from the surface to inside of the target object OBJ 1 , depending on the amount of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5 , as if the movement objects OBJ 2   a  and OBJ 2   b  were pushed into the target object OBJ 1 . When as shown in  FIG.  14    the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is in the steady state, i.e., is not deformed, and the user is extending the knees (the left controller  3  is in an upright position, i.e., the negative y-axis direction of the left controller  3  points in the vertically downward direction), the movement objects OBJ 2   a  and OBJ 2   b  are located along an outer peripheral side surface at a top portion of the target object OBJ 1 . Note that the movement objects OBJ 2   a  and OBJ 2   b  correspond to a non-limiting example of an object disposed in a virtual space. The direction in which the movement objects OBJ 2   a  and OBJ 2   b  are moved vertically along the surface of the target object OBJ 1  corresponds to a non-limiting example of a second direction in which an object is moved. The direction in which the movement objects OBJ 2   a  and OBJ 2   b  are moved from the surface to inside of the target object OBJ 1  as if the movement objects OBJ 2   a  and OBJ 2   b  were pushed into the target object OBJ 1  corresponds to a non-limiting example of a first direction in which an object is moved. 
     Meanwhile, as shown in  FIG.  15   , when an operation of deforming the ring-shaped portion  201  from the steady state so that the grip covers  203  and  204  move toward each other (a pressing operation for deformation in a B direction shown in  FIG.  15   ) is performed, a pair of the movement objects OBJ 2   a  and OBJ 2   b  are each moved into the target object OBJ 1 , depending on the amount of deformation, as if the movement objects OBJ 2   a  and OBJ 2   b  were pushed into the target object OBJ 1 . Specifically, the movement object OBJ 2   a  disposed along the outer peripheral side surface on the left side of the target object OBJ 1 , is moved rightward (a j-direction shown in  FIG.  15   ) into the target object OBJ 1  in a movement amount corresponding to the amount of deformation as if the movement object OBJ 2   a  were pushed into the target object OBJ 1 . The movement object OBJ 2   b  disposed along the outer peripheral side surface on the right side of the target object OBJ 1 , is moved into the target object OBJ 1  leftward (a j-direction shown in  FIG.  15   ) in a movement amount corresponding to the amount of deformation as if the movement object OBJ 2   b  were pushed into the target object OBJ 1 . By a pair of the movement objects OBJ 2   a  and OBJ 2   b  being thus moved from the outer peripheral side surface to inside of the target object OBJ 1  as if the movement objects OBJ 2   a  and OBJ 2   b  were pushed into the target object OBJ 1 , the target object OBJ 1  is deformed as if the outer peripheral side surface were cut or carved. Specifically, the target object OBJ 1  is deformed by portions thereof in contact with a pair of the movement objects OBJ 2   a  and OBJ 2   b  being cut in a cut amount corresponding to the amount of deformation of the ring-shaped extension apparatus  5 . Note that the target object OBJ 1  may be a hard object that can be cut by the movement objects OBJ 2   a  and OBJ 2   b , or a fluid (e.g. a plastic fluid) or elastic solid that can be dented by the movement objects OBJ 2   a  and OBJ 2   b . In the latter case, when the movement objects OBJ 2   a  and OBJ 2   b  are moved from the outer surface to inside of the target object OBJ 1  as if the movement objects OBJ 2   a  and OBJ 2   b  were pushed into the target object OBJ 1 , the target object OBJ 1  may be deformed so that the target object OBJ 1  is dented at the pressed portions, and a part of the dented portion is displaced upward and downward. In that case, the target object OBJ 1  is deformed as if the target object OBJ 1  were pressed by the movement objects OBJ 2   a  and OBJ 2   b.    
     Such a pressing operation of deforming the ring-shaped extension apparatus  5  is detected based on a strain detected by the strain gauge provided in the ring-shaped extension apparatus  5 . When the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is deformed from the steady state, a strain of the base portion is detected by the strain gauge. Based on the detected strain, a direction in which the ring-shaped portion  201  is deformed (i.e., a direction in which the two grip covers  203  and  204  move away from each other or toward each other) and the amount of deformation can be calculated. If the direction in which the ring-shaped portion  201  is deformed is the direction in which the two grip covers  203  and  204  move toward each other, a pair of the movement objects OBJ 2   a  and OBJ 2   b  are moved rightward and leftward, depending on the calculated amount of deformation, to cut a portion of the target object OBJ 1 , so that the target object OBJ 1  can be deformed. Note that when the pressing operation is removed, a pair of the movement objects OBJ 2   a  and OBJ 2   b  end the action of cutting the target object OBJ 1 , and are disposed at the locations where the movement objects OBJ 2   a  and OBJ 2   b  are in contact with the outer peripheral side surface of the target object OBJ 1 . Note that the amount in which the movement objects OBJ 2   a  and OBJ 2   b  cut the target object OBJ 1  may be calculated so that the cut amount at an inner portion of the target object OBJ 1  is greater than the cut amount at an outer portion of the target object OBJ 1 . 
     When the user performs an action of bending and extending the knees, the belt-shaped extension apparatus  6  fastened to the user&#39;s left thigh is also moved. For example, the left controller  3  attached to the belt-shaped extension apparatus  6  fastened to the front portion of the user&#39;s left thigh, is moved according to the user&#39;s action of bending and extending the knees so that the left controller  3  is swayed around an axis extending in the lateral horizontal direction of the user perpendicular to the gravitational direction (vertically downward direction) in the real space, between an upright state (the longitudinal direction of the left controller  3  points in the vertically downward direction) and an elevation angle state (the longitudinal direction of the left controller  3  is closer to the front-back horizontal direction of the user than in the upright state) (a sway in an M direction in  FIG.  15   , also referred to as a “front-back sway”). In a non-limiting example, in the case where the left controller  3  is attached to the belt-shaped extension apparatus  6  so that the negative y-axis direction of the left controller  3  points in the vertically downward direction of the real space (i.e., the positive y-axis direction of the left controller  3  points in the vertically upward direction in the real space) when the user is standing still with their left foot on a floor, the body of the left controller  3  is moved to rotate around an axis extending in the user&#39;s lateral horizontal direction (the x-axis direction of the left controller  3 ) according to the user&#39;s bending of the knees so that the left controller  3  is transitioned from the upright state in which the negative y-axis direction of the left controller  3  points in the vertically downward direction to the elevation angle state in which the negative y-axis direction of the left controller  3  is closer to the horizontal direction than in the upright state. 
     In order to calculate a bending angle of the user&#39;s action of bending and extending the knees, an angle of the user&#39;s thigh (e.g., the left thigh) with reference to the gravitational acceleration may be calculated. The angle of the user&#39;s thigh may be calculated using at least one of an angular velocity and acceleration occurring on the left controller  3  using any suitable technique. In a non-limiting example, the calculation may be performed using both an angular velocity and acceleration occurring on the left controller  3 . In a first non-limiting example, by adding up angular velocities around the x-axis direction occurring on the left controller  3 , the orientation of the left controller  3  with reference to the gravitational acceleration, i.e., the bending angle of the user&#39;s action of bending and extending the knees, can be calculated. In a second non-limiting example, by detecting the direction of the gravitational acceleration acting on the left controller  3 , and calculating an angle difference between the longitudinal direction (y-axis direction) of the left controller  3  and the direction of the gravitational acceleration, the bending angle of the user&#39;s action of bending and extending the knees can be calculated. 
     As shown in  FIG.  15   , when the user performs an action of bending and extending the knees with the belt-shaped extension apparatus  6  fastened to the front portion of the left thigh, a pair of the movement objects OBJ 2   a  and OBJ 2   b  are moved vertically (an i-direction shown in  FIG.  15   ) according to the bending angle of the knee. Specifically, when the user&#39;s knee is fully extended (the longitudinal direction of the left controller  3  is in an upright position), the movement objects OBJ 2   a  and OBJ 2   b  are disposed at locations where the movement objects OBJ 2   a  and OBJ 2   b  are in contact with uppermost positions on the outer peripheral side surface of the target object OBJ 1 . As the bending angle of the user&#39;s knee becomes gradually greater, the movement objects OBJ 2   a  and OBJ 2   b  move downward along the outer peripheral side surface of the target object OBJ 1 . Here, the movement objects OBJ 2   a  and OBJ 2   b  are maintained at locations where the movement objects OBJ 2   a  and OBJ 2   b  are in contact with the outer peripheral side surface of the target object OBJ 1 , and therefore, even when the movement objects OBJ 2   a  and OBJ 2   b  are being moved vertically according to the bending angle of the knee, the movement objects OBJ 2   a  and OBJ 2   b  are kept in contact with the outer peripheral side surface of the target object OBJ 1 . In other words, even when a portion of the outer peripheral side surface of the target object OBJ 1  is being cut, the movement objects OBJ 2   a  and OBJ 2   b  are moved along the shape of the outer peripheral side surface that is being cut. 
     Thus, the vertical locations of a pair of the movement objects OBJ 2   a  and OBJ 2   b  can be controlled according to the bending angle of the knees in the user&#39;s action of bending and extending the knees. Therefore, by adjusting the amount of deformation by a pressing operation performed on the ring-shaped extension apparatus  5  while adjusting the vertical locations of the movement objects OBJ 2   a  and OBJ 2   b , the user can cut the outer peripheral side surface of the target object OBJ 1  at any suitable locations in any suitable amounts, and thereby deform the target object OBJ 1 . In a first non-limiting example game, a sample image SP that is a goal of deformation of the target object OBJ 1  is displayed, and game points are calculated based on a similarity between the deformed target object OBJ 1  and the sample image SP. 
     Note that the user&#39;s operation of bending and extending the knees may be determined using an output of the right controller  4  or other input apparatuses in addition to an output of a motion sensor included in the left controller  3  (the belt-shaped extension apparatus  6 ). 
     In the first non-limiting example game, in a non-limiting example, when an operation of vertically moving the movement objects OBJ 2   a  and OBJ 2   b  is performed simultaneously with a pressing operation for deforming the ring-shaped extension apparatus  5  to deform the target object OBJ 1 , the operation of deforming the target object OBJ 1  may be continued while the movement objects OBJ 2   a  and OBJ 2   b  are being moved vertically. Alternatively, in another non-limiting example, when an operation of vertically moving the movement objects OBJ 2   a  and OBJ 2   b  is performed simultaneously with a pressing operation for deforming the ring-shaped extension apparatus  5  to deform the target object OBJ 1 , one of these operations may be performed with higher priority. For example, when an operation of vertically moving the movement objects OBJ 2   a  and OBJ 2   b  is performed simultaneously with a pressing operation for deforming the ring-shaped extension apparatus  5  to deform the target object OBJ 1 , the operation of deforming the target object OBJ 1  may be temporarily stopped, and the vertical movement of the movement objects OBJ 2   a  and OBJ 2   b  may be performed with higher priority, and after the vertical movement, when the operation of pressing the ring-shaped extension apparatus  5  is temporarily removed and is resumed, the operation of deforming the target object OBJ 1  may be resumed. 
     Next, a non-limiting example of a specific process that is executed by the game system  1  in the first non-limiting example game will be described with reference to  FIGS.  16 - 19   .  FIG.  16    is a diagram showing a non-limiting example of a data area contained in the DRAM  85  of the main body apparatus  2  in the first non-limiting example game. Note that in addition to the data of  FIG.  16   , the DRAM  85  also stores data that is used in other processes, which will not be described in detail. 
     In the first non-limiting example game, various programs Pa that are executed in the game system  1  are stored in a program storage area of the DRAM  85 . In this non-limiting example, the programs Pa include a communication program for performing wireless communication with the right controller  4 , an application program (e.g., a game program) for performing information processing based on data obtained from the right controller  4 , etc. Note that the programs Pa may be previously stored in the flash memory  84 , may be obtained from a storage medium removably attached to the game system  1  (e.g., a predetermined type of storage medium attached to the slot  23 ) and then stored in the DRAM  85 , or may be obtained from another apparatus via a network, such as the Internet, and then stored in the DRAM  85 . The processor  81  executes the programs Pa stored in the DRAM  85 . 
     In the first non-limiting example game, various kinds of data that are used in processes such as a communication process and an information process that are executed in the game system  1  are stored in a data storage area of the DRAM  85 . In this non-limiting example, the DRAM  85  stores operation data Daa, angular velocity data Dab, acceleration data Dac, orientation data Dad, gravitational direction data Dae, ring deformation amount data Dag, knee bending angle data Dah, cut amount data Dai, score data Daj, movement object action data Dak, target object shape data Dam, and image data Dan, etc. 
     The operation data Daa is obtained from each of the left controller  3  and the right controller  4  as appropriate. As described above, the operation data transmitted from the left controller  3  and the right controller  4  includes information about an input from each input section (specifically, each button, an analog stick, or each sensor) (specifically, information about an operation, and the result of detection by each sensor), and a strain value indicating a state of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5 . In this non-limiting example, operation data is transmitted from each of the left controller  3  and the right controller  4  at predetermined time intervals through wireless communication. The received operation data is used to update the operation data Daa as appropriate. Note that the operation data Daa may be updated for each frame that is the cycle of a process executed in the game system  1 , or may be updated each time operation data is received through the wireless communication. 
     The angular velocity data Dab indicates the history of angular velocities occurring on each of the left controller  3  and the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The angular velocities are included in the operation data obtained from the left controller  3  and the right controller  4 . For example, the angular velocity data Dab includes the history of data indicating angular velocities about the x-, y-, and z-axes occurring on each of the left controller  3  and the right controller  4 , etc. 
     The acceleration data Dac indicates the history of accelerations occurring on each of the left controller  3  and the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The accelerations are included in the operation data obtained from the left controller  3  and the right controller  4 . For example, the acceleration data Dac includes the history of data indicating accelerations in the x-, y-, and z-axis directions occurring on each of the left controller  3  and the right controller  4 , etc. 
     The orientation data Dad indicates an orientation of each of the left controller  3  and the right controller  4  in the real space. In a non-limiting example, the orientation data Dad indicates the x-, y-, and z-axis directions (e.g., angles with respect to X, Y, and Z axes in the real space) of the left controller  3  and the right controller  4  in the real space. 
     The gravitational direction data Dae indicates the direction of a gravitational acceleration acting on each of the left controller  3  and the right controller  4 . 
     The ring deformation amount data Dag indicates the direction and amount of deformation of the ring-shaped extension apparatus  5 . 
     The knee bending angle data Dah indicates the bending angle of the knee that the user bends and extends. 
     The cut amount data Dai indicates the amount of the target object OBJ 1  that is cut for deformation. 
     The score data Daj indicates a current game score. 
     The movement object action data Dak indicates the locations, states, orientations, actions, etc., of the movement objects OBJ 2   a  and OBJ 2   b  disposed in the virtual game space. The target object shape data Dam indicates the shape of the target object OBJ 1 . 
     The image data Dan is for displaying an image (e.g., an image of the target object OBJ 1 , images of the movement objects OBJ 2   a  and OBJ 2   b , a field image, a background image, etc.) on a display screen. 
     Next, a specific non-limiting example of an information process in the first non-limiting example game will be described with reference to  FIGS.  17 - 19   .  FIG.  17    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1 .  FIG.  18    is a subroutine showing a specific non-limiting example of a vertical movement process that is performed in step S 505  shown in  FIG.  17   .  FIG.  19    is a subroutine of a specific non-limiting example of a cutting process that is performed in step S 506  shown in  FIG.  17   . In the first non-limiting example game, a series of processes shown in  FIGS.  17 - 19    are performed by the processor  81  executing a communication program and a predetermined application program (game program) included in the programs Pa. The information process of  FIGS.  17 - 19    is started with any suitable timing. 
     Note that the steps in the flowchart of  FIGS.  17 - 19   , which are merely illustrative, may be executed in a different order, or another step may be executed in addition to (or instead of) each step, if a similar effect is obtained. In this non-limiting example, it is assumed that the processor  81  executes each step of the flowchart. Alternatively, a portion of the steps of the flowchart may be executed by a processor or dedicated circuit other than the processor  81 . In addition, a portion of the steps executed by the main body apparatus  2  may be executed by another information processing apparatus that can communicate with the main body apparatus  2  (e.g., a server that can communicate with the main body apparatus  2  via a network). Specifically, the steps of  FIGS.  17 - 19    may be executed by a plurality of information processing apparatuses including the main body apparatus  2  cooperating with each other. 
     In  FIG.  17    the processor  81  performs initial setting for the information process (step S 501 ), and proceeds to the next step. For example, in the initial setting, the processor  81  initializes parameters for performing processes to be described below. For example, the processor  81  initially disposes, in the virtual game space, objects (including the target object OBJ 1 , and the movement objects OBJ 2   a  and OBJ 2   b ) to generate an initial state of the virtual game space, and updates the movement object action data Dak with the locations, directions, and orientations, etc., of the movement objects OBJ 2   a  and OBJ 2   b . The processor  81  also updates the target object shape data Dam with the initial shape of the target object OBJ 1 . The processor  81  also sets the sample image SP indicating a goal of the following game. 
     Next, the processor  81  obtains operation data from each of the left controller  3  and the right controller  4  and updates the operation data Daa (step S 502 ), and proceeds to the next step. Note that the processor  81  stores data indicating an angular velocity occurring on each of the left controller  3  and the right controller  4 , which is included in the operation data obtained from each of the left controller  3  and the right controller  4  in step S 502 , into the angular velocity data Dab. The processor  81  also stores data indicating an acceleration occurring on each of the left controller  3  and the right controller  4 , which is included in the operation data obtained from each of the left controller  3  and the right controller  4  in step S 502 , into the acceleration data Dac. 
     Next, the processor  81  calculates the orientation of the left controller  3  (step S 503 ), and proceeds to the next step. For example, the processor  81  obtains the angular velocities about the x-, y-, and z-axes of the left controller  3  using angular velocity data stored in the angular velocity data Dab. Thereafter, the processor  81  turns the x-, y-, and z-axes with reference to the gravitational acceleration direction of the orientation of the left controller  3  indicated by the orientation data Dad, based on the respective angular velocities obtained, and stores the directions of the turned x-, y-, and z-axes with reference to the gravitational acceleration direction, as most recent data indicating the orientation of the left controller  3 , into the orientation data Dad. The processor  81  also calculates the direction of the gravitational acceleration acting on the left controller  3  using acceleration data stored in the acceleration data Dac, and stores the calculated direction into the gravitational direction data Dae. Note that the gravitational acceleration may be extracted using any suitable technique. For example, an acceleration component averagely occurring on the left controller  3  may be calculated and extracted as the gravitational acceleration. The processor  81  may also corrects, as appropriate, the most recent orientation of the left controller  3  indicated by the orientation data Dad using the direction of the gravitational acceleration occurring on the left controller  3  indicated by the gravitational direction data Dae. 
     Next, the processor  81  calculates the amount of deformation of the ring-shaped extension apparatus  5  (step S 504 ), and proceeds to the next step. For example, the processor  81  calculates the amount and direction of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  using a strain value indicated by the operation data Daa, and updates the ring deformation amount data Dag with the calculation result. 
     Next, the processor  81  performs a vertical movement process (step S 505 ), and proceeds to step S 506 . The vertical movement process performed in step S 505  will be described with reference to  FIG.  18   . Note that second control is a process that is executed on an object based on motion data, and in a non-limiting example, corresponds to the vertical movement process performed the processor  81 . 
     In  FIG.  18   , the processor  81  calculates a knee bending angle (step S 521 ), and proceeds to the next step. For example, the processor  81  calculates the knee bending angle using the orientation of the left controller  3  calculated in step S 503 , and updates the knee bending angle data Dah with the calculated knee bending angle. In a non-limiting example, the processor  81  calculates an angle difference between the gravitational acceleration direction and the negative y-axis direction using the orientation of the left controller  3  with reference to the gravitational acceleration indicated by the gravitational direction data Dae, and sets the angle difference as the knee bending angle. 
     Next, the processor  81  calculates a vertical location of the movement objects corresponding to the knee bending angle calculated in step S 521  (step S 522 ), and proceeds to the next step. For example, the processor  81  calculates the vertical location of the movement objects so that the vertical location of the movement objects is an uppermost location of the target object OBJ 1  when the knee bending angle is zero degrees, and the vertical location of the movement object becomes gradually closer to a lowermost location of the target object OBJ 1  as the bending angle of the user&#39;s knee increases. 
     Next, the processor  81  calculates the location of each of the movement objects OBJ 2   a  and OBJ 2   b  (step S 523 ), and ends the process of the subroutine. For example, the processor  81  calculates locations on both left and right sides where the movement objects OBJ 2   a  and OBJ 2   b  are in contact with the outer peripheral side surface of the target object OBJ 1  at the vertical locations calculated in step S 521 , and updates the movement object action data Dak with the locations. 
     Referring back to  FIG.  17   , after the vertical movement process in step S 505 , the processor  81  performs a cutting process (step S 506 ), and proceeds to step S 507 . The cutting process performed in step S 506  will now be described with reference to  FIG.  19   . Note that first control corresponds to a process that is executed on an object based on strain data, and in a non-limiting example, corresponds to the cutting process performed by the processor  81 . 
     In  FIG.  19   , the processor  81  calculates a cut amount (step S 531 ), and proceeds to the next step. For example, the processor  81  calculates the cut amount in which the target object OBJ 1  is cut by the movement objects OBJ 2   a  and OBJ 2   b , based on the amount of deformation calculated in step S 504 , and updates the cut amount data Dai with the cut amount. In a non-limiting example, the cut amount calculated by the processor  81  increases with an increase in the amount of deformation. Note that the calculated cut amount may increase relatively as the locations of the movement objects OBJ 2   a  and OBJ 2   b  calculated in step S 523  is closer to the center axis of the target object OBJ 1 . Note that the above technique of deforming the target object OBJ 1  is merely illustrative, and the target object OBJ 1  may be deformed using other techniques. For example, in the case where the target object OBJ 1  is formed of a plastic fluid or an elastic solid, the target object OBJ 1  may be deformed by a physical simulation between the target object OBJ 1  and the movement objects OBJ 2   a  and OBJ 2   b , which are a hard object, using a more complex expression. 
     Next, the processor  81  moves the movement objects OBJ 2   a  and OBJ 2   b  rightward and leftward, depending on the cut amount (step S 532 ), and proceeds to the next step. For example, the processor  81  moves the locations of the movement objects OBJ 2   a  and OBJ 2   b  rightward and leftward toward the center axis of the target object OBJ 1  by an amount corresponding to the cut amount, and updates the movement object action data Dak with the locations of the movement objects OBJ 2   a  and OBJ 2   b  after the movement. 
     Next, the processor  81  performs a process of deforming the target object OBJ 1  (step S 533 ), and ends the process of the subroutine. For example, the processor  81  calculates a shape of the target object OBJ 1  that is obtained after a portion of the outer peripheral side surface of the target object OBJ 1  indicated by the target object shape data Dam has been cut by the movement objects OBJ 2   a  and OBJ 2   b  being moved to the locations calculated in step S 532  as if the movement objects OBJ 2   a  and OBJ 2   b  were pushed into the target object OBJ 1 , and updates the target object shape data Dam with the calculated shape. 
     Referring back to  FIG.  17   , after the cutting process in step S 506 , the processor  81  performs an action control process on the objects (the movement objects OBJ 2   a  and OBJ 2   b , etc.), and proceeds to the next step. For example, the processor  81  disposes the movement objects OBJ 2   a  and OBJ 2   b  in the virtual game space based on the locations, states, orientations, actions, etc., of the movement objects OBJ 2   a  and OBJ 2   b  indicated by the movement object action data Dak. 
     Next, the processor  81  determines whether or not to end the process of cutting the target object OBJ 1  and thereby changing the shape of the target object OBJ 1  (step S 508 ). The condition for ending the cutting process in step S 508  is, for example, that a predetermined time limit for changing the shape of the target object OBJ 1  has passed, that the user has performed an operation of ending changing of the shape of the target object OBJ 1 , etc. If the processor  81  determines to end the cutting process, the processor  81  proceeds to step S 509 . Otherwise, i.e., if the processor  81  does not determine to end the cutting process, the processor  81  proceeds to step S 510 . 
     In step S 509 , the processor  81  performs a determination process, and proceeds to step S 510 . For example, the processor  81  calculates game points based on a similarity between the shape of the target object OBJ 1  indicated by the target object shape data Dam and a shape that is a goal of the game (e.g., the shape of an image displayed as the sample image SP), and updates the score data Daj with the game points. 
     In step S 510 , the processor  81  performs an image generation and display control process, and proceeds to the next step. For example, the processor  81  disposes the target object OBJ 1  having a shape indicated by the target object shape data Dam in the virtual game space where the movement objects OBJ 2   a  and OBJ 2   b  are disposed. The processor  81  also disposes a virtual camera in the virtual game space, generates a virtual game space image as viewed from the virtual camera, and outputs the virtual game space image to the stationary monitor  9 . The processor  81  also disposes the sample image SP set in step S 501  as an appropriate portion of the virtual game space image, and outputs the resultant image to the stationary monitor  9 . The processor  81  also causes an image indicating a game score indicated by the score data Daj to overlay an appropriate portion of the virtual game space image, and outputs the resultant image to the stationary monitor  9 . 
     Next, the processor  81  determines whether or not to end the game process (step S 511 ). The condition for ending the game process in step S 511  is, for example, that the condition for ending the game process is satisfied, that the user has performed an operation of ending the game process, etc. If the processor  81  does not determine to end the game process, the processor  81  returns to step S 502 , and repeats the process. If the processor  81  determines to end the game process, the processor  81  ends the process of the flowchart. Thereafter, steps S 502 -S 511  are repeatedly executed until the processor  81  determines, in step S 511 , to end the game process. 
     Thus, in the first non-limiting example game, control is performed so that the movement objects OBJ 2   a  and OBJ 2   b  cuts and deforms the target object OBJ 1  according to a pressing operation of deforming the ring-shaped extension apparatus  5 , and control is performed so that the movement objects OBJ 2   a  and OBJ 2   b  are moved vertically according to the motion of the belt-shaped extension apparatus  6  caused by the user bending and extending the knees. Therefore, the variety of user inputs using both the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6  can be increased. 
     Second Non-limiting Example Game 
     Next, before describing a specific process in a second non-limiting example game performed by the main body apparatus  2 , the second non-limiting example game performed in the main body apparatus  2  will be outlined with reference to  FIGS.  20 - 23   . Note that  FIG.  20    is a diagram showing a non-limiting example of how, in the second non-limiting example game, the user operates the ring-shaped extension apparatus  5 .  FIG.  21    is a diagram showing a first non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the second non-limiting example game.  FIG.  22    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the second non-limiting example game.  FIG.  23    is a diagram showing a third non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the second non-limiting example game. 
     As shown in  FIG.  20   , in the second non-limiting example game, the user holds one (e.g., the grip cover  203 ) of the grip covers of the ring-shaped extension apparatus  5 , and places the other grip cover (e.g., the grip cover  204 ) in contact with the user&#39;s abdomen. Then, the user performs an operation with the ring-shaped extension apparatus  5  sandwiched between both hands and the abdomen. Specifically, the user performs an operation of tilting the ring-shaped extension apparatus  5  to the left and right while deforming the ring-shaped extension apparatus  5  so that the grip covers  203  and  204  move toward each other in the ring-shaped extension apparatus  5  sandwiched between both hands and the abdomen. Here, in order to tilt the ring-shaped extension apparatus  5  to the left and right with the ring-shaped extension apparatus  5  sandwiched between both hands and the abdomen of the user, the user tilts the upper body to the left and right. Therefore, in the second non-limiting example game, the user is required to perform a gaming operation of tilting the entire body to the left and right while exerting a force so that both hands move toward the abdomen. In the second non-limiting example game, the user also performs an operation of stamping the feet with the belt-shaped extension apparatus  6  fastened to the user&#39;s thigh. Specifically, in the second non-limiting example game, while the user is performing an operation of deforming the ring-shaped extension apparatus  5  and an operation of tilting the ring-shaped extension apparatus  5  to the left and right, the user is also performing an action of stamping the feet so that the belt-shaped extension apparatus  6  fastened to the user&#39;s thigh is moved. 
     As described above, in the game system  1  of this non-limiting example, the left controller  3  and the right controller  4  are removable from the main body apparatus  2 . In addition, as shown in  FIGS.  21 - 23   , when the main body apparatus  2  alone is attached to the cradle  8 , an image (and sound) can be output from the stationary monitor  9 . The game system  1  will now be described, assuming the situation that the left controller  3  and the right controller  4  are removed from the main body apparatus  2 , the main body apparatus  2  alone is attached to the cradle  8 , and an image (and sound) is output from the stationary monitor  9  connected to the cradle  8 . In a non-limiting example, the user performs a gaming operation using the right controller  4  attached to the ring-shaped extension apparatus  5  and the left controller  3  attached to the belt-shaped extension apparatus  6 . In a non-limiting example of a game process in the second non-limiting example game, a process is used in which a player character PC displayed on the stationary monitor  9  walks and moves in the virtual game space, maintaining balance using a balance pole having objects OBJL and OBJR at left and right ends thereof, according to the user&#39;s operation. Note that the player character PC corresponds to another example of an object disposed in the virtual space. 
     For example, in  FIG.  21   , the player character PC is disposed in the virtual game space. The player character PC stands still, holding the center of the balance pole having the object OBJL at the left end and the object OBJR at the right end. The balance pole can be changed to a shortened state in which the length between the object OBJL at the left end and the object OBJR at the right end is short, and an extended state in which the length between the object OBJL at the left end and the object OBJR at the right end is long. When the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is in the steady state, i.e., is not deformed, as shown in  FIG.  21   , the balance pole is in the shortened state. Note that the player character PC, when having the balance pole in the extended state, is in an action mode in which the player character PC is allowed to walk and move according to the user&#39;s stamping-foot operation, and when having the balance pole in the shortened state, is in an action mode in which the player character PC is not allowed to walk or move even when the user performs a stamping-foot operation. The example of  FIG.  21    shows a state in which the user is standing still (the left controller  3  is in a vertical position, i.e., the negative y-axis direction of the left controller  3  points in the vertically downward direction), and is not performing a stamping-foot operation or an operation of tilting the body to the left and right. 
     Meanwhile, when the user performs an operation of deforming the ring-shaped portion  201  of the ring-shaped extension apparatus  5  from the steady state to at least a predetermined state so that the grip covers  203  and  204  move toward each other as shown in  FIG.  22    (a pressing operation for deformation in a B direction shown in  FIG.  22   ), the balance pole is changed to the extended state in which the length between the object OBJL at the left end and the object OBJR at the right end is long, and the player character PC is put into an action mode in which the player character PC is allowed to walk. Such a pressing operation is detected based on a strain detected by the strain gauge provided in the ring-shaped extension apparatus  5 . When the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is deformed from the steady state, a strain of the base portion is detected by the strain gauge. Based on the detected strain, a direction in which the ring-shaped portion  201  is deformed (i.e., a direction in which the two grip covers  203  and  204  move away from each other or toward each other) and the amount of deformation can be calculated. If the direction in which the ring-shaped portion  201  is deformed is the direction in which the two grip covers  203  and  204  move toward each other, and the amount of deformation is greater than or equal to a preset threshold, it is determined that a pressing operation for changing the left and right objects OBJL and OBJR to the extended state has been performed. Note that when the pressing operation is removed, the balance pole is changed to the shortened state, and the player character PC is put into an action mode in which the player character PC is not allowed to walk. Note that the example of  FIG.  22    shows a state in which the user is standing still (the left controller  3  is in the vertical position, i.e., the negative y-axis direction of the left controller  3  points in the vertically downward direction), and is not performing a stamping-foot operation or an operation of tilting the body to the left and right. Note that whether or not an operation of pressing the ring-shaped extension apparatus  5  has been performed may be determined by methods other than the method of determining whether or not the calculated amount of deformation is greater than or equal to a preset threshold. For example, the presence or absence of the pressing operation may be determined simply based on whether or not a strain has been detected by the strain sensor of the ring-shaped extension apparatus  5 , irrespective of the threshold. 
     When the user performs a stamping-foot action as shown in  FIG.  23   , the belt-shaped extension apparatus  6  fastened to the user&#39;s left thigh is also moved. For example, the left controller  3  attached to the belt-shaped extension apparatus  6  fastened to the front portion of the user&#39;s left thigh, is moved according to the user&#39;s stamping-foot action so that the left controller  3  is swayed around an axis extending in the lateral horizontal direction of the user perpendicular to the gravitational direction (vertically downward direction) in the real space, between an upright state (the longitudinal direction of the left controller  3  points in the vertically downward direction) and an elevation angle state (the longitudinal direction of the left controller  3  is closer to the front-back horizontal direction of the user than in the upright state) (a sway in an M direction in  FIG.  23   ). In a non-limiting example, in the case where the left controller  3  is attached to the belt-shaped extension apparatus  6  so that the negative y-axis direction of the left controller  3  points in the vertically downward direction of the real space (i.e., the positive y-axis direction of the left controller  3  points in the vertically upward direction in the real space) when the user is standing still with their left foot on a floor, the body of the left controller  3  is moved to rotate around an axis extending in the user&#39;s lateral horizontal direction (the x-axis direction of the left controller  3 ) according to the user&#39;s action of raising the left thigh so that the left controller  3  is transitioned from the upright state in which the negative y-axis direction of the left controller  3  points in the vertically downward direction to the elevation angle state in which the negative y-axis direction of the left controller  3  is closer to the horizontal direction than in the upright state. 
     A method for detecting when the user starts to move (i.e., starts a stamping-foot operation) from a rest state, using the left controller  3  attached to the belt-shaped extension apparatus  6 , will be described. In a non-limiting example, if it is determined that the value of an acceleration occurring on the left controller  3  in the vertically upward direction of the real space excluding the gravitational acceleration is greater than or equal to a predetermined threshold, i.e., it is determined that the left controller  3  is accelerated in the vertically upward direction of the real space, or if it is determined that a change in an angle by which the left controller  3  performs the above sway action is greater than or equal to a predetermined threshold, it can be determined that the user has started a stamping-foot action. After the user has started a stamping-foot action, if it is determined that a change in the angle or acceleration of the left controller  3  during a predetermined period of time is smaller than or equal to a predetermined threshold, or if it is determined that an angular velocity change amount or average angular velocity value of the left controller  3  during a predetermined period of time is smaller than or equal to a predetermined threshold, it can be determined that the user has stopped a stamping-foot action. 
     In order to calculate intervals during the user&#39;s stamping-foot action (stamping-foot intervals, i.e., intervals at which the user&#39;s left thigh with the belt-shaped extension apparatus  6  fastened thereto is moved up and down), it is necessary to detect the user&#39;s action of moving a thigh (e.g. the left thigh) up and down. The determination of upward and downward movements of a thigh for detecting the user&#39;s action of moving a thigh up and down may be performed using any suitable technique using at least one of an angular velocity and acceleration occurring on the left controller  3 . In a non-limiting example, the determination may be performed using both an angular velocity and acceleration occurring on the left controller  3 . Specifically, maximum and minimum values of an angle around the x-axis direction of the left controller  3  during a predetermined period of time (the angle increases with an increase in the knee bending angle) are obtained, and if the time at which the maximum value was obtained is more recent than the time at which the minimum value was obtained, and the acceleration in the vertically downward direction of the left controller  3  is smaller than or equal to a predetermined threshold, i.e., the left controller  3  is being accelerated in the vertically upward direction of the real space, it can be determined that the current state is a thigh raising state. Maximum and minimum values of an angle around the x-axis direction of the left controller  3  during a predetermined period of time are obtained, and if the time at which the minimum value was obtained is more recent than the time at which the maximum value was obtained, and the acceleration in the vertically downward direction of the left controller  3  is greater than or equal to a predetermined threshold, i.e., the left controller  3  is being accelerated in the vertically downward direction of the real space, it can be determined that the current state is a thigh lowering state. 
     As described above, when it is determined that the user is performing a stamping-foot action, and therefore, the player character PC is in the action mode that the player character PC is allowed to move, the player character PC is displayed that is walking and moving in the virtual game space with an action and velocity corresponding to the user&#39;s stamping-foot action. For example, based on the result of the determination of the user&#39;s stamping-foot action or the determination of the user&#39;s action of moving the thigh up and down, the action of the player character PC may be controlled to change the movement velocity of the player character PC so that the user and the player character PC perform the same motion. Specifically, based on the result of the determination of the user&#39;s action of moving the thigh up and down, the player character PC&#39;s action of walking or running is controlled so that the player character PC raises the left leg synchronously with the user&#39;s action of raising the left leg, and raises the right leg simultaneously with the user&#39;s action of raising the right leg, and therefore, unnaturalness (deviation) with respect to the user&#39;s operation can be reduced. 
     When the user performs an operation of tilting the ring-shaped extension apparatus  5  to the left and right (a roll operation of turning the ring-shaped extension apparatus  5  in an N direction shown in  FIG.  23   ) while performing the pressing operation as shown in  FIG.  23   , the player character PC performs an action of tilting the balance pole in the extended state in a direction corresponding to the roll operation. As used herein, an operation of tilting the ring-shaped extension apparatus  5  to the left refers to an operation of rolling the ring-shaped extension apparatus  5  so that the circular-ring axis of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is turned around the front-back direction of the user (e.g., around the y-axis direction of the right controller  4 ) to be tilted to the left while a pressing operation is performed on the ring-shaped portion  201  of the ring-shaped extension apparatus  5  with the circular-ring axis of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  pointing in the vertically downward direction (i.e., in a state in which the ring-shaped portion  201  is in a horizontal position) in the real space. When a roll operation of tilting the ring-shaped extension apparatus  5  to the left while the pressing operation is being performed, the player character PC tilts the balance pole in the extended state to the left (i.e., a state in which the object OBJL at the left end is lowered and the object OBJR at the right end is raised with respect to the equilibrium state). 
     When a roll operation of tilting the ring-shaped extension apparatus  5  to the left and right is thus performed, an angular velocity around the front-back direction of the user (e.g., around the y-axis direction of the right controller  4 ) occurs on the right controller  4  attached to the ring-shaped extension apparatus  5 , and the direction of the gravitational acceleration acting on the right controller  4  is changed. Therefore, the operation direction and operation angle, etc., of a roll operation of tilting the ring-shaped extension apparatus  5  to the left and right can be calculated using an acceleration detected by the acceleration sensor  114  of the right controller  4  and/or an angular velocity detected by the angular velocity sensor  115  of the right controller  4 . In the second non-limiting example game, when a roll operation of tilting the ring-shaped extension apparatus  5  to the left and right is performed while the pressing operation is being performed, an action of tilting the balance pole in the operation direction by the operation angle is performed. Actually, a roll operation of tilting the ring-shaped extension apparatus  5  to the left and right may be a combination of a roll operation, pitch operation, and yaw operation on the ring-shaped extension apparatus  5 . Therefore, a final operation direction and operation angle may be calculated by combining operation directions and operation angles of the ring-shaped extension apparatus  5  that are changed by the roll operation, pitch operation, and yaw operation. 
     Here, a plurality of obstruction objects H, etc., that obstruct the walk movement of the player character PC are disposed in the virtual game space. The obstruction objects H are disposed on the left and right sides of a path on which the player character PC walks and moves, and may hit the object OBJL at the left end or the object OBJR at the right end, depending on the tilt angle of the balance pole. Specifically, in order to avoid hitting the obstruction objects H, it is necessary to cause the player character PC to walk and move while adjusting the tilt angle of the balance pole so that the object OBJL at the left end and the object OBJR at the right end are prevented from hitting the obstruction objects H. Therefore, the user is required to perform an operation of continuing the walk movement of the player character PC while avoiding hitting the obstruction objects H by performing a roll operation of tilting the ring-shaped extension apparatus  5  to the left and right while causing the player character PC to walk and move by performing a stamping-foot operation using a leg with the belt-shaped extension apparatus  6  fastened thereto while performing an operation of pressing the ring-shaped extension apparatus  5 . 
     Note that a reward object that can give game points may also be disposed on the left and right sides of a path on which the player character PC walks and moves. When the object OBJL at the left end or the object OBJR at the right end hits a reward object, game points set for the reward object can be obtained. Therefore, a lot of game points can be obtained by actively hitting reward objects with the object OBJL at the left end or the object OBJR at the right end. In that case, the user is required to perform an operation of continuing the walk movement of the player character PC while actively trying to hit reward objects by performing a roll operation of tilting the ring-shaped extension apparatus  5  to the left and right while causing the player character PC to walk and move by performing a stamping-foot operation using a leg with the belt-shaped extension apparatus  6  fastened thereto while performing an operation of pressing the ring-shaped extension apparatus  5 . 
     Thus, in the second non-limiting example game, a process of changing the orientation of the player character PC according to the motion of the ring-shaped extension apparatus  5  is performed, and when the player character PC is moving in an orientation that causes the player character PC to hit an obstruction object H, the movement may be obstructed, and the game score is decreased, and when the player character PC is moving in an orientation that causes the player character PC to hit a reward object, the game score may be increased. In other words, in the second non-limiting example game, when the player character PC has a predetermined orientation at a predetermined location in the virtual game space, the user is given an in-game merit. Note that examples of the in-game merit include an increase and decrease in game score, the presence and absence of a movement obstruction, and in addition, an acceleration and deceleration of the movement velocity, an increase and decrease in challenge level of a game, and a success and failure in obtaining a game item. Various merits may be given to the user. Whether or not to give the in-game merits may be determined based on the distance or number of steps from the location of the start instead of the location of the player character PC. Alternatively, whether or not to give the in-game merits may be determined based on data indicating the motion of the ring-shaped extension apparatus  5 , i.e., data detected by the inertial sensor of the right controller  4  itself, instead of the orientation of the player character PC. 
     Note that the player character PC&#39;s actions of walking and moving and tilting the balance pole may be allowed only when an operation of pressing the ring-shaped extension apparatus  5  is being performed. In that case, once the operation of pressing the ring-shaped extension apparatus  5  has been removed, then when an operation of pressing the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is performed again, the player character PC&#39;s actions of walking and moving and tilting the balance pole are allowed. 
     The threshold (extension threshold) for determining the amount of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  in order to determine that the pressing operation has been changed from the ineffective state (the pressing operation is not being performed) to the effective state (the pressing operation is effective), and the threshold (shortening threshold) for determining that the pressing operation has been changed from the effective state (the pressing operation is being performed) to the ineffective state (the pressing operation is ineffective), may be different from each other. For example, the shortening threshold may be smaller than the extension threshold. In that case, even in a state that the force exerted on the pressing operation is reduced due to a roll operation or stamping-foot operation performed on the ring-shaped extension apparatus  5  after the pressing operation, a situation that the balance pole is changed back to the shortened state, so that the player character PC&#39;s actions of walking and moving and/or tilting the balance pole are stopped, can be prevented to some extent. Note that the extension threshold corresponds to a non-limiting example of a first threshold, and the shortening threshold corresponds to a non-limiting example of a second threshold. 
     The user&#39;s stamping-foot operation may be determined using not only the motion of the belt-shaped extension apparatus  6  (the left controller  3 ) but also the motion of the ring-shaped extension apparatus  5  (the right controller  4 ) or the outputs of other input apparatuses. For example, at least one of determination of start of the user&#39;s stamping-foot operation, determination of stopping of the user&#39;s stamping-foot operation, and determination of upward and downward movement of the thigh during the user&#39;s stamping-foot operation, may be performed using an acceleration and/or angular velocity occurring on the ring-shaped extension apparatus  5  (the right controller  4 ) as well. The roll operation using the ring-shaped extension apparatus  5  may be determined using not only the output of the motion sensor included in the right controller  4  (the ring-shaped extension apparatus  5 ) but also the output of the left controller  3  or the outputs of other input apparatuses. The user&#39;s stamping-foot operation may be determined using the motion of the ring-shaped extension apparatus  5  (the right controller  4 ) or the outputs of other input apparatuses, instead of the motion of the belt-shaped extension apparatus  6  (the left controller  3 ). In the former case, in the second non-limiting example game, a game may be played by a gaming operation using only the belt-shaped extension apparatus  6 . 
     Next, a non-limiting example of a specific process that is executed by the game system  1  in the second non-limiting example game will be described with reference to  FIGS.  24 - 28   .  FIG.  24    is a diagram showing a non-limiting example of a data area contained in the DRAM  85  of the main body apparatus  2  in the second non-limiting example game. Note that in addition to the data of  FIG.  24   , the DRAM  85  also stores data that is used in other processes, which will not be described in detail. 
     In the second non-limiting example game, various programs Pb that are executed in the game system  1  are stored in a program storage area of the DRAM  85 . In this non-limiting example, the programs Pb include a communication program for performing wireless communication with the right controller  4 , an application program (e.g., a game program) for performing information processing based on data obtained from the right controller  4 , etc. Note that the programs Pb may be previously stored in the flash memory  84 , may be obtained from a storage medium removably attached to the game system  1  (e.g., a predetermined type of storage medium attached to the slot  23 ) and then stored in the DRAM  85 , or may be obtained from another apparatus via a network, such as the Internet, and then stored in the DRAM  85 . The processor  81  executes the programs Pb stored in the DRAM  85 . 
     In the second non-limiting example game, various kinds of data that are used in processes such as a communication process and an information process that are executed in the game system  1  are stored in a data storage area of the DRAM  85 . In this non-limiting example, the DRAM  85  stores operation data Dba, angular velocity data Dbb, acceleration data Dbc, orientation data Dbd, gravitational direction data Dbe, ring deformation amount data Dbg, extended and shortened state data Dbh, walking action data Dbi, thigh raising/lowering action data Dbj, score data Dbk, player character action data Dbm, obstruction object action data Dbn, and image data Dbp, etc. 
     The operation data Dba is obtained from each of the left controller  3  and the right controller  4  as appropriate. As described above, the operation data transmitted from the left controller  3  and the right controller  4  includes information about an input from each input section (specifically, each button, an analog stick, or each sensor) (specifically, information about an operation, and the result of detection by each sensor), and a strain value indicating a state of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5 . In this non-limiting example, operation data is transmitted from each of the left controller  3  and the right controller  4  at predetermined time intervals through wireless communication. The received operation data is used to update the operation data Dba as appropriate. Note that the operation data Dba may be updated for each frame that is the cycle of a process executed in the game system  1 , or may be updated each time operation data is received through the wireless communication. 
     The angular velocity data Dbb indicates the history of angular velocities occurring on each of the left controller  3  and the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The angular velocities are included in the operation data obtained from the left controller  3  and the right controller  4 . For example, the angular velocity data Dbb includes the history of data indicating angular velocities about the x-, y-, and z-axes occurring on each of the left controller  3  and the right controller  4 , etc. 
     The acceleration data Dbc indicates the history of accelerations occurring on each of the left controller  3  and the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The accelerations are included in the operation data obtained from the left controller  3  and the right controller  4 . For example, the acceleration data Dbc includes the history of data indicating accelerations in the x-, y-, and z-axis directions occurring on each of the left controller  3  and the right controller  4 , etc. 
     The orientation data Dbd indicates an orientation of each of the left controller  3  and the right controller  4  in the real space, and indicates the history of orientations thereof that have been obtained during a period of time from the current time to a predetermined time before. In a non-limiting example, the orientation data Dbd indicates the history of the x-, y-, and z-axis directions (e.g., angles with respect to X, Y, and Z axes in the real space) of each of the left controller  3  and the right controller  4  in the real space. 
     The gravitational direction data Dbe indicates the direction of a gravitational acceleration acting on each of the left controller  3  and the right controller  4 . 
     The ring deformation amount data Dbg indicates the direction and amount of deformation of the ring-shaped extension apparatus  5 . 
     The extended and shortened state data Dbh indicates a state (e.g., the extended state or shortened state) of the balance pole. The walking action data Dbi indicates a walk state (e.g., the rest state or walking state) of the player character PC. The thigh raising/lowering action data Dbj indicates the times that the thigh is raised and lowered in the user&#39;s stamping-foot operation. 
     The score data Dbk indicates the current game score. 
     The player character action data Dbm indicates the location, state, orientation, action, etc., of the player character PC disposed in the virtual game space. The obstruction object action data Dbn indicates the location, state, orientation, action, etc., of an obstruction object H disposed in the virtual game space. 
     The image data Dbp is for displaying an image (e.g., an image of the player character PC, an image of the balance pole, an image of an obstruction object H, a field image, a background image, etc.) on a display screen. 
     Next, a specific non-limiting example of an information process in the second non-limiting example game will be described with reference to  FIGS.  25 - 28   .  FIG.  25    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1  in the second non-limiting example game.  FIG.  26    is a subroutine showing a specific non-limiting example of an extension and shortening process that is performed in step S 605  shown in  FIG.  25   .  FIG.  27    is a subroutine of a specific non-limiting example of a tilting process that is performed in step S 606  shown in  FIG.  25   .  FIG.  28    is a subroutine of a specific non-limiting example of a walking process that is performed in step S 607  shown in  FIG.  25   . In the second non-limiting example game, a series of processes shown in  FIGS.  25 - 28    are performed by the processor  81  executing a communication program and a predetermined application program (game program) included in the programs Pb. The information process of  FIGS.  25 - 28    is started with any suitable timing. 
     Note that the steps in the flowchart of  FIGS.  25 - 28   , which are merely illustrative, may be executed in a different order, or another step may be executed in addition to (or instead of) each step, if a similar effect is obtained. In this non-limiting example, it is assumed that the processor  81  executes each step of the flowchart. Alternatively, a portion of the steps of the flowchart may be executed by a processor or dedicated circuit other than the processor  81 . In addition, a portion of the steps executed by the main body apparatus  2  may be executed by another information processing apparatus that can communicate with the main body apparatus  2  (e.g., a server that can communicate with the main body apparatus  2  via a network). Specifically, the steps of  FIGS.  25 - 28    may be executed by a plurality of information processing apparatuses including the main body apparatus  2  cooperating with each other. 
     In  FIG.  25   , the processor  81  performs initial setting for the information process (step S 601 ), and proceeds to the next step. For example, in the initial setting, the processor  81  initializes parameters for performing processes to be described below. For example, the processor  81  initially disposes, in the virtual game space, objects (including the player character PC holding the balance pole) to generate an initial state of the virtual game space, and updates the extended and shortened state data Dbh, the walking action data Dbi, the player character action data Dbm, and the obstruction object action data Dbn with the location, direction, state, and orientation, etc., of each object. Note that the processor  81  initially sets the state of the player character PC to a rest state in which the player character PC holds the balance pole in the shortened state. 
     Next, the processor  81  obtains operation data from each of the left controller  3  and the right controller  4  and updates the operation data Dba (step S 602 ), and proceeds to the next step. Note that the processor  81  stores data indicating an angular velocity occurring on each of the left controller  3  and the right controller  4 , which is included in the operation data obtained from each of the left controller  3  and the right controller  4  in step S 602 , into the angular velocity data Dbb. The processor  81  also stores data indicating an acceleration occurring on each of the left controller  3  and the right controller  4 , which is included in the operation data obtained from each of the left controller  3  and the right controller  4  in step S 602 , into the acceleration data Dbc. 
     Next, the processor  81  calculates the orientation of each of the left controller  3  and the right controller  4  (step S 603 ), and proceeds to the next step. For example, the processor  81  obtains the angular velocities about the x-, y-, and z-axes of each of the left controller  3  and the right controller  4  using angular velocity data stored in the angular velocity data Dbb. Thereafter, the processor  81  turns the x-, y-, and z-axes with reference to the gravitational acceleration direction of the orientation of each of the left controller  3  and the right controller  4  indicated by the orientation data Dbd, based on the respective angular velocities obtained, and stores the directions of the turned x-, y-, and z-axes with reference to the gravitational acceleration direction, as most recent data indicating the orientation of each of the left controller  3  and the right controller  4 , into the orientation data Dbd. The processor  81  also calculates the direction of the gravitational acceleration acting on each of the left controller  3  and the right controller  4  using acceleration data stored in the acceleration data Dbc, and stores the calculated directions into the gravitational direction data Dbe. Note that the gravitational acceleration may be extracted using any suitable technique. For example, an acceleration component averagely occurring on each of the left controller  3  and the right controller  4  may be calculated and extracted as the gravitational acceleration. The processor  81  may also corrects, as appropriate, the most recent orientation of each of the left controller  3  and the right controller  3  indicated by the orientation data Dbd using the direction of the gravitational acceleration occurring on each of the left controller  3  and the right controller  4  indicated by the gravitational direction data Dbe. 
     Next, the processor  81  calculates the amount of deformation of the ring-shaped extension apparatus  5  (step S 604 ), and proceeds to the next step. For example, the processor  81  calculates the amount and direction of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  using a strain value indicated by the operation data Dba, and updates the ring deformation amount data Dbg with the calculation result. 
     Next, the processor  81  performs an extension and shortening process (step S 605 ), and proceeds to step S 606 . The extension and shortening process performed in step S 605  will now be described with reference to  FIG.  26   . Note that first control corresponds to a process that is executed on an object based on strain data, and in another non-limiting example, corresponds to the extension and shortening process performed by the processor  81 . 
     In  FIG.  26   , the processor  81  determines whether or not the balance pole is in the shortened state (step S 521 ). For example, the processor  81  determines, with reference to the extended and shortened state data Dbh, whether or not the balance pole is in the shortened state. If the balance pole is in the shortened state, the processor  81  proceeds to step S 622 . Otherwise, i.e., if the balance pole is in the extended state, the processor  81  proceeds to step S 624 . 
     In step S 622 , the processor  81  determines whether or not the amount of deformation calculated in step S 604  is greater than or equal to an extension threshold. If the amount of deformation is greater than or equal to the extension threshold, the processor  81  proceeds to step S 623 . Otherwise, i.e., if the amount of deformation is smaller than the extension threshold, the processor  81  ends the process of the subroutine. Here, the extension threshold is used to determine the amount of deformation of the ring-shaped extension apparatus  5  in order to detect when a pressing operation performed on the ring-shaped extension apparatus  5  is started. If the amount of deformation of the ring-shaped extension apparatus  5  has reached the extension threshold or higher, it is determined that the pressing operation has been started. 
     In step S 623 , the processor  81  sets the state of the balance pole to the extended state, and ends the process of the subroutine. For example, the processor  81  sets the state of the balance pole to the extended state to update the extended and shortened state data Dbh. 
     Meanwhile, if it is determined in step S 621  that the balance pole is in the extended state, the processor  81  determines whether or not the amount of deformation calculated in step S 604  is greater than or equal to a shortening threshold. If the amount of deformation is greater than or equal to the shortening threshold, the processor  81  proceeds to step S 623 . Otherwise, i.e., if the amount of deformation is smaller than the shortening threshold, the processor  81  proceeds to step S 625 . Here, the shortening threshold is used for determining that the pressing operation is continued even when the pressing force exerted on the ring-shaped extension apparatus  5  is reduced after the start of the pressing operation performed on the ring-shaped extension apparatus  5 , and therefore, is set to a value smaller than the extension threshold. 
     In step S 625 , the processor  81  sets the state of the balance pole to the shortened state, and ends the process of the subroutine. For example, the processor  81  sets the state of the balance pole to the shortened state to update the extended and shortened state data Dbh. 
     Referring back to  FIG.  25   , after the extension and shortening process in step S 605 , the processor  81  performs a tilting process (step S 606 ), and proceeds to step S 607 . The tilting process performed in step S 606  will now be described with reference to  FIG.  27   . Note that third control corresponds to a process of changing the orientation of an object based on motion data output from the first input apparatus, and in a non-limiting example, corresponds to the tilting process performed by the processor  81 . 
     In  FIG.  27   , the processor  81  determines whether or not the balance pole is in the extended state (step S 631 ). For example, the processor  81  determines, with reference to the extended and shortened state data Dbh, whether or not the balance pole is in the extended state. If the balance pole is in the extended state, the processor  81  proceeds to step S 632 . Otherwise, i.e., if the balance pole is in the shortened state, the processor  81  proceeds to step S 634 . 
     In step S 632 , the processor  81  calculates a tilt angle (operation angle) of the ring-shaped extension apparatus  5  in the real space, and proceeds to the next step. For example, the processor  81  calculates an operation direction and operation angle of a roll operation of tilting the ring-shaped extension apparatus  5  with respect to the direction of the gravitational acceleration (e.g., an angle difference between the direction of the gravitational acceleration and the x-axis direction or z-axis direction) using the orientation of the right controller  4  indicated by the orientation data Dbd. 
     Next, the processor  81  calculates the tilt angle of the balance pole (step S 633 ), and proceeds to step S 635 . For example, the processor  81  calculates the tilt angle of the balance pole corresponding to the operation direction and operation angle of a roll operation performed on the ring-shaped extension apparatus  5  calculated in step S 632  (e.g., the tilt angle by which the balance pole is tilted in the same direction as the operation direction of a roll operation performed on the ring-shaped extension apparatus  5  and at the same angle as the operation angle of the roll operation), and updates the player character action data Dbm with the tilt angle of the balance pole. 
     Meanwhile, if it is determined in step S 631  that the balance pole is in the shortened state, the processor  81  sets the balance pole to the equilibrium state, and proceeds to step S 635 . For example, the processor  81  updates the player character action data Dbm with the set equilibrium state of the balance pole. 
     In step S 635 , the processor  81  sets the orientation of the player character PC, and ends the process of the subroutine. For example, the processor  81  sets the orientation of the player character PC based on the state (tilt angle) of the balance pole set in step S 633  or S 634 , and updates the player character action data Dbm with the set orientation. 
     Referring back to  FIG.  25   , after the tilting process in step S 606 , the processor  81  performs a walking process (step S 607 ), and proceeds to step S 608 . The walking process performed in step S 607  will now be described with reference to  FIG.  28   . Note that second control is a process that is executed on an object based on motion data, and in another non-limiting example, corresponds to the walking process performed by the processor  81 . 
     In  FIG.  28   , the processor  81  determines whether or not the balance pole is in the extended state (step S 641 ). For example, the processor  81  determines, with reference to the extended and shortened state data Dbh, whether or not the balance pole is in the extended state. If the balance pole is in the extended state, the processor  81  proceeds to step S 642 . Otherwise, i.e., if the balance pole is in the shortened state, the processor  81  proceeds to step S 648 . 
     In step S 642 , the processor  81  determines whether or not the player character PC is in the rest state. For example, if the state indicated by the walking action data Dbi is the rest state, the result of determination in step S 642  by the processor  81  is positive. If the player character PC is in the rest state, the processor  81  proceeds to step S 643 . If the player character PC is in the walking state, the processor  81  proceeds to step S 646 . 
     In step S 643 , the processor  81  calculates an acceleration occurring on the left controller  3  in the vertically upward direction of the real space excluding the gravitational acceleration, and proceeds to the next step. For example, the processor  81  obtains an acceleration occurring on the left controller  3  in the vertically upward direction of the real space (an acceleration in an opposite direction from the gravitational acceleration) using the acceleration data Dbc and the gravitational direction data Dbe, and subtracts the gravitational acceleration from the acceleration in the vertically upward direction. 
     Next, the processor  81  determines whether or not the user has performed an action of starting to walk (starting a stamping-foot operation) (step S 644 ). For example, if the acceleration of the left controller  3  in the vertically upward direction that has been calculated in step S 643  is greater than or equal to a predetermined threshold indicating the start of walking, the result of determination in step S 644  by the processor  81  is positive. If the user has performed an action of starting to walk (starting a stamping-foot operation), the processor  81  proceeds to step S 645 . Otherwise, i.e., if the user has not performed an action of starting to walk (starting a stamping-foot operation), the processor  81  proceeds to step S 657 . 
     In step S 645 , the processor  81  sets the player character PC to the walking state, and proceeds to step S 649 . For example, the processor  81  sets the state indicated by the walking action data Dbi to the walking state to update the walking action data Dbi. 
     Meanwhile, if the processor  81  determines in step S 642  that the player character PC is in the walking state, the processor  81  calculates an angle change amount and/or angular velocity change amount of the left controller  3  during a most recent predetermined period of time (step S 646 ), and proceeds to the next step. For example, the processor  81  obtains angular velocities occurring on the left controller  3  during a most recent predetermined period of time using the angular velocity data Dbb, and calculates, using the angular velocities, the angle change amount of the left controller  3  during that predetermined period of time and/or the angular velocity change amount of the left controller  3  during that predetermined period of time. 
     Next, the processor  81  determines whether or not the user has performed an action of stopping the stamping-foot operation (step S 647 ). For example, if the angle change amount calculated in step S 646  is smaller than or equal to a predetermined threshold indicating stopping of a stamping-foot action, and/or if the angular velocity displace amount calculated in step S 646  is smaller than or equal to a predetermined threshold indicating stopping of a stamping-foot action, the result of determination in step S 647  by the processor  81  is positive. If the user has performed an action of stopping the stamping-foot operation, the processor  81  proceeds to step S 648 . Otherwise, i.e., if the user has not performed an action of stopping the stamping-foot operation, the processor  81  proceeds to step S 645 . 
     In step S 648 , the processor  81  sets the player character PC to the rest state, and proceeds to step S 657 . For example, the processor  81  sets the state indicated by the walking action data Dbi to the rest state to update the walking action data Dbi. Note that if it is determined in step S 641  that the balance pole is in the shortened state as described above, or if the balance pole is in the shortened state as a result of step S 648  as described above, the player character PC is set to the rest state, so that the player character PC is set to an action mode in which the player character PC is not allowed to move. 
     If the player character PC is in the walking state, the user&#39;s stamping-foot state is determined. After step S 645 , the processor  81  obtains a maximum value and minimum value of an angle of the left controller  3  in the front-back direction (e.g., around the x-axis direction) having occurred during a most recent predetermined period of time (step S 649 ), and proceeds to the next step. For example, the processor  81  obtains an angular velocity of the left controller  3  in the user&#39;s front-back direction (e.g., around the x-axis direction) having occurred during a most recent predetermined period of time using the angular velocity data Dbb, and obtains a maximum value and minimum value of an angle in the front-back direction (the angle increases with an increase in the knee bending angle) calculated from the angular velocity. 
     Next, the processor  81  determines whether or not the time that the maximum value was obtained in step S 649  is more recent than the time that the minimum value was obtained in step S 649  (step S 650 ). If the time that the maximum value was obtained is more recent, the processor  81  proceeds to step S 651 . Otherwise, i.e., if the time that the minimum value was obtained is more recent, the processor  81  proceeds to step S 654 . 
     In step S 651 , the processor  81  obtains an acceleration of the left controller  3  in the vertically downward direction having occurred during a most recent predetermined period of time, and proceeds to the next step. For example, the processor  81  obtains an acceleration of the left controller  3  in the vertically downward direction having occurred during a most recent predetermined period of time using the acceleration data Dbc. 
     Next, the processor  81  determines whether or not the acceleration obtained in step S 651  is smaller than or equal to a thigh raising threshold for determining that the direction of an acceleration is the vertically upward direction of the real space (step S 652 ). If the acceleration obtained in step S 651  is smaller than or equal to the thigh raising threshold, the processor  81  determines that the left controller  3  is being accelerated in the vertically upward direction of the real space, and proceeds to step S 653 . Otherwise, i.e., if the acceleration obtained in step S 651  is greater than the thigh raising threshold, the processor  81  determines that the left controller  3  is not being accelerated in the vertically upward direction of the real space, and proceeds to step S 657 . 
     In step S 653 , the processor  81  sets the time that the maximum value of the angle of the left controller  3  in the front-back direction (e.g., around the x-axis direction) was obtained, as a thigh raising time, and proceeds to step S 657 . For example, the processor  81  sets the time that the maximum value obtained in step S 649  was obtained, as a thigh raising time, and if that thigh raising time is a most recent thigh raising time, updates the thigh raising/thigh lowering action data Dbn with that thigh raising time. 
     Meanwhile, in step S 654 , the processor  81  obtains an acceleration of the left controller  3  in the vertically downward direction having occurred during a most recent predetermined period of time, and proceeds to the next step. For example, the processor  81  obtains an acceleration of the left controller  3  in the vertically downward direction having occurred during a most recent predetermined period of time using the acceleration data Dbc. 
     Next, the processor  81  determines whether or not the acceleration obtained in step S 654  is greater than or equal to a thigh lowering threshold for determining that the direction of an acceleration is the vertically downward direction of the real space (step S 655 ). If the acceleration obtained in step S 654  is greater than or equal to the thigh lowering threshold, the processor  81  determines that the left controller  3  is being accelerated in the vertically downward direction of the real space, and proceeds to step S 656 . Otherwise, i.e., if the acceleration obtained in step S 654  is smaller than the thigh lowering threshold, the processor  81  determines that the left controller  3  is not being accelerated in the vertically downward direction of the real space, and proceeds to step S 657 . 
     In step S 656 , the processor  81  sets the time that the minimum value of the angle of the left controller  3  in the front-back direction (e.g., around the x-axis direction) as a thigh lowering time, and proceeds to step S 657 . For example, the processor  81  sets the time that the minimum value obtained in step S 649  was obtained, as a thigh raising time, and if that thigh lowering time is a most recent thigh lowering time, updates the thigh raising/thigh lowering action data Dbn using that thigh lowering time. 
     In step S 657 , the processor  81  sets a walking action of the player character PC, and ends the process of the subroutine. For example, the processor  81  sets the player character PC to the walking state or rest state based on the state indicated by the walking action data Dbi to update the player character action data Dbm. If the player character PC is in the walking state, the processor  81  sets a state of the legs of the player character PC walking at the current time, based on the timing of the thigh raising time and thigh lowering time indicated by the thigh raising/thigh lowering action data Dbn, to update the player character action data Dbm. 
     Referring back to  FIG.  25   , after the walking process in step S 607 , the processor  81  performs an action control process on the player character PC (step S 608 ), and proceeds to the next step. For example, the processor  81  disposes the player character PC in the virtual game space based on the locations, states, orientations, actions, etc., of the player character PC and the balance pole indicated by the player character action data Dbm. 
     Next, the processor  81  performs an action control process on an object (step S 609 ), and proceeds to the next step. For example, if an obstruction object H has been hit by the balance pole, based on the location of the obstruction object H indicated by the obstruction object action data Dbp and the location of the balance pole (the object OBJL at the left end and the object OBJR at the right end) indicated by the player character action data Dbm, the processor  81  updates the obstruction object action data Dbp so as to display a scene that the obstruction object H performs an attack and disappears in the virtual game space, and changes a game score based on the attack to update the score data Dbk. The processor  81  also causes an obstruction object H to appear in the virtual game space, according to a predetermined algorithm (appearance pattern), and updates the obstruction object action data Dbp with the location of the obstruction object H after the appearance. The processor  81  disposes the obstruction object H in the virtual game space based on the location, state, orientation, action, etc., of the obstruction object H indicated by the obstruction object action data Dbp. 
     Next, the processor  81  performs an image generation and display control process (step S 610 ), and proceeds to the next step. For example, the processor  81  disposes a virtual camera in the virtual game space in which the player character PC and the obstruction object H, etc., have been disposed in steps S 608  and S 609 , generates an image of the virtual game space as viewed from the virtual camera, and outputs the virtual game space image to the stationary monitor  9 . The processor  81  also causes an image indicating the game score indicated by the score data Dbk to overlay the virtual game space image at an appropriate position, and outputs the resultant image to the stationary monitor  9 . 
     Next, the processor  81  determines whether or not to end the game process (step S 611 ). The condition for ending the game process in step S 611  is, for example, that the condition for ending the game process is satisfied, that the user has performed an operation of ending the game process, etc. If the processor  81  does not determine to end the game process, the processor  81  returns to step S 602 , and repeats the process. If the processor  81  determines to end the game process, the processor  81  ends the process of the flowchart. Thereafter, steps S 602 -S 611  are repeatedly executed until the processor  81  determines, in step S 611 , to end the game process. 
     Thus, in the second non-limiting example game, the control of switching between the action mode in which the player character PC is allowed to move according to a pressing operation of deforming the ring-shaped extension apparatus  5 , and the action mode in which the player character PC is not allowed to move, the control of changing the state of the balance pole, and the control of causing the player character PC to walk and move according to the motion of the belt-shaped extension apparatus  6  caused by a stamping-foot action, are performed. Therefore, the variety of user inputs using both of the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6  can be increased. 
     Third Non-limiting Game Example 
     Next, before describing a specific process in a third non-limiting example game performed by the main body apparatus  2 , the third non-limiting example game performed in the main body apparatus  2  will be outlined with reference to  FIGS.  29 - 32   . Note that  FIG.  29    is a diagram showing a non-limiting example of how, in the third non-limiting example game, the user operates the ring-shaped extension apparatus  5 .  FIG.  30    is a diagram showing a first non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the third non-limiting example game.  FIG.  31    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the third non-limiting example game.  FIG.  32    is a diagram showing a third non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the third non-limiting example game. 
     As shown in  FIG.  29   , in the third non-limiting example game, the user holds one (e.g., the grip cover  203 ) of the grip covers of the ring-shaped extension apparatus  5  with both hands, and places the other grip cover (e.g., the grip cover  204 ) in contact with the user&#39;s abdomen. Then, the user performs an operation with the ring-shaped extension apparatus  5  sandwiched between both hands and the abdomen. Specifically, the user performs an operation of moving the ring-shaped extension apparatus  5  to the left and right, i.e., swinging the ring-shaped extension apparatus  5  from side to side, while deforming the ring-shaped extension apparatus  5  so that the grip covers  203  and  204  move toward each other in the ring-shaped extension apparatus  5  sandwiched between both hands and the abdomen. Here, in order to swing, to the left and right, the ring-shaped extension apparatus  5  with the ring-shaped extension apparatus  5  sandwiched between both hands and the abdomen of the user, the user turns the entire abdomen, i.e., the user&#39;s waist, to the left and right. Therefore, in the third non-limiting example game, the user is required to perform a gaming operation of twisting the waist while exerting a force so that both hands approach the abdomen. 
     As described above, in the game system  1  of this non-limiting example, the left controller  3  and the right controller  4  are removable from the main body apparatus  2 . In addition, as shown in  FIGS.  30 - 32   , when the main body apparatus  2  alone is attached to the cradle  8 , an image (and sound) can be output from the stationary monitor  9 . The game system  1  will now be described, assuming the situation that the left controller  3  and the right controller  4  are removed from the main body apparatus  2 , the main body apparatus  2  alone is attached to the cradle  8 , and an image (and sound) is output from the stationary monitor  9  connected to the cradle  8 . In a non-limiting example, the user performs a gaming operation using the right controller  4  attached to the ring-shaped extension apparatus  5 . In a non-limiting example of a game process in the third non-limiting example game, a process is used in which a player character PC displayed on the stationary monitor  9  moves a left object OBJL and a right object OBJR according to the user&#39;s operation to knock down (attack) a target object T in a virtual game space. 
     For example, in  FIG.  30   , the player character PC is disposed in the virtual game space. The player character PC is equipped with the object OBJL on the left side thereof and the object OBJR on the right side thereof. The left and right objects OBJL and OBJR are changeable between an open state in which the player character PC can knock down a target object T and a closed state in which the player character PC cannot knock down a target object T. As shown in  FIG.  30   , when the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is in the steady state that the ring-shaped portion  201  is not deformed, the left and right objects OBJL and OBJR are in the closed state. 
     Meanwhile, as shown in  FIG.  31   , when an operation of deforming the ring-shaped extension apparatus  5  so that the grip covers  203  and  204  are moved toward each other and thereby the ring-shaped portion  201  is changed from the steady state to at least a predetermined state (a pressing operation to deform the ring-shaped extension apparatus  5  in a B direction shown in  FIG.  14   ) is performed, the left and right objects OBJL and OBJR are moved to the left and right of the player character PC to be open to the left and right, respectively, i.e., is changed to the open state that allows the player character PC to knock down a target object T. Such a pressing operation is detected based on a strain detected by the strain gauge provided in the ring-shaped extension apparatus  5 . When the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is deformed from the steady state, a strain of the base portion is detected by the strain gauge. Based on the detected strain, a direction in which the ring-shaped portion  201  is deformed (i.e., a direction in which the two grip covers  203  and  204  move away from each other or toward each other) and the amount of deformation can be calculated. If the direction in which the ring-shaped portion  201  is deformed is the direction in which the two grip covers  203  and  204  move toward each other, and the amount of deformation is greater than or equal to a preset threshold, it is determined that a pressing operation for obtaining the state that the left and right objects OBJL and OBJR are open has been performed. Note that when the pressing operation is stopped, the left and right objects OBJL and OBJR are moved backward relative to the player character PC to be closed, i.e., the left and right objects OBJL and OBJR are changed to the closed state that the player character PC cannot knock down a target object T. In this case, game points that could be obtained by knock downing a target object T cannot be obtained, and the degree of game achievement cannot be updated. Therefore, in a non-limiting example, when the left and right objects OBJL and OBJR are in the closed state, the user may be prompted to perform an operation of deforming the ring-shaped extension apparatus  5 , by providing to the user a predetermined image or sound (e.g., a text image “press the ring-shaped extension apparatus  5 ” or a voice “press the ring-shaped extension apparatus  5 ”). In another non-limiting example, when the left and right objects OBJL and OBJR are in the closed state, then even if an operation of swinging the ring-shaped extension apparatus  5  to the left and right is performed, a scene may be created and displayed that the left and right objects OBJL and OBJR miss a target object T and therefore do not knock down the target object T, and thereby the user may be prompted to perform an operation of deforming the ring-shaped extension apparatus  5 . 
     As shown in  FIG.  32   , a plurality of target objects T (in  FIG.  32   , target objects T 1  and T 2 ) to be attacked by the player character PC approach the player character PC from the front of the player character PC. The player character PC can strike a target object T with one of the left and right objects OBJL and OBJR to attack, i.e., knock down and eliminate, the target object T. By knocking down a target object T, the user can obtain a predetermined number of game points. 
     For example, as shown in  FIG.  32   , when an operation of swinging the ring-shaped extension apparatus  5  to the right while performing the above pressing operation is performed, the player character PC performs an action of turning both of the left and right objects OBJL and OBJR so that the left object OBJL in the open state is turned toward the front while the right object OBJR is turned toward the back. Here, the operation of swinging the ring-shaped extension apparatus  5  to the right is such that in the real space, while the pressing operation is performed with a circular-ring axis of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  pointing in a vertically downward direction, i.e., in the vertical position (i.e., the ring-shaped portion  201  is horizontally disposed, i.e., in the horizontal position), the ring-shaped extension apparatus  5  is turned around the circular-ring axis to the right (a C direction in  FIG.  15   ) with the circular-ring axis maintained in the vertical position and moving to the right. When an operation of swinging the ring-shaped extension apparatus  5  to the left is performed while performing the pressing operation, the player character PC performs an action of turning both of the left and right objects OBJL and OBJR so that the right object OBJR in the open state is turned toward the front while the left object OBJL is turned toward the back. Here, the operation of swinging the ring-shaped extension apparatus  5  to the left is such that in the real space, while the pressing operation is performed with the circular-ring axis of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  in the vertical position, the ring-shaped extension apparatus  5  is turned around the circular-ring axis to the left with the circular-ring axis maintained in the vertical position and moving in the left. 
     Thus, when the operation of swinging the ring-shaped extension apparatus  5  to the left or right is performed, an acceleration occurs toward the horizontal direction of the real space and an angular velocity occurs around the z-axis direction (see  FIG.  6   ), on the right controller  4  attached to the ring-shaped extension apparatus  5 . Therefore, by using an acceleration detected by the acceleration sensor  114  of the right controller  4  and/or an angular velocity detected by the angular velocity sensor  115  of the right controller  4 , a direction, angle, and speed, etc., of the operation of swinging the ring-shaped extension apparatus  5  to the left or right can be calculated. In the third non-limiting example game, when the ring-shaped extension apparatus  5  is swung by at least a predetermined operation angle while performing the pressing operation, it is determined that the operation of swinging toward that direction has been performed. Actually, the operation of swinging the ring-shaped extension apparatus  5  to the left or right may be a combination of a roll operation, pitch operation, and yaw operation on the ring-shaped extension apparatus  5 . Therefore, a final operation angle or operation velocity may be calculated by combining directions of the ring-shaped extension apparatus  5  that are changed by the roll operation, pitch operation, and yaw operation. 
     Here, the operation angle for determining that a swinging operation has been performed may be the angle of rotation around the circular-ring axis of the ring-shaped extension apparatus  5  by which an orientation of the ring-shaped extension apparatus  5  is changed from a reference orientation that is an orientation of the ring-shaped extension apparatus  5  at the time that the pressing operation is performed, where the operation angle occurring when the ring-shaped extension apparatus  5  is in the reference orientation is zero. Thus, the user can reset the operation angle to zero by performing the pressing operation after returning the ring-shaped extension apparatus  5  to the steady state. Note that there may be some time difference between the time at which the pressing operation is performed and the time at which the reference orientation (i.e., the operation angle) of the ring-shaped extension apparatus  5  is set to zero. For example, the orientation of the ring-shaped extension apparatus  5  that occurs when a predetermined period of time has passed since the pressing operation may be set to the reference orientation, i.e., the operation angle occurring at that time may be set to zero. The angular velocity sensor  115  of the right controller  4  attached to the ring-shaped extension apparatus  5  has a tendency to accumulate noise when continuing detection, and eventually fails to detect an accurate angular velocity, resulting in a so-called “drift” in detected values. Even when errors are thus accumulated in the detection value of the angular velocity sensor  115 , then if the operation angle is initialized to zero with the ring-shaped extension apparatus  5  returned to the steady state, the direction (e.g., the front direction) with an operation angle of zero can be reset while the errors are removed. 
     The operation of turning both of the left and right objects OBJL and OBJR may be allowed once for a single pressing operation. In a non-limiting example, after the action of swinging the left and right objects OBJL and OBJR has been performed, the left and right objects OBJL and OBJR may be moved toward the back of the player character PC to be closed and are thereby changed to the closed state in which the player character PC cannot knock down a target object T, even when the pressing operation is continued. In that case, when the user desires to move the left and right objects OBJL and OBJR in the open state several times, the user is required to return the ring-shaped portion  201  of the ring-shaped extension apparatus  5  once to the steady state and then perform the pressing operation again before next performing the operation of swinging the ring-shaped extension apparatus  5 . 
     Note that the operation of providing a command to turn both of the left and right objects OBJL and OBJR may be input before displaying the player character PC&#39;s action. For example, when the player character PC is performing an action of swinging the left and right objects OBJL and OBJR, then if the pressing operation of the ring-shaped extension apparatus  5  is once stopped and then the pressing operation is newly performed, the operation of providing a command to turn both of the left and right objects OBJL and OBJR may be allowed to be input in response to the new pressing operation, in advance, even when the player character PC&#39;s action is still being displayed. The number of times the above operation can be input in advance during the player character PC&#39;s action may be limited (e.g., the number of times the operation can be input in advance is limited to once). 
     A threshold (first threshold) for determining the amount of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  at which the pressing operation can be determined to be changed to the effective state from the state that the pressing operation is not being performed, may be different from a threshold (second threshold) for determining the amount of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  at which the pressing operation can be determined to be changed to the ineffective state from the state that the pressing operation is being performed. For example, in the case where the second threshold is smaller than the first threshold, even when the force for the pressing operation is reduced due to the operation of swinging the ring-shaped extension apparatus  5  during the pressing operation, the situation that the left and right objects OBJL and OBJR are returned to the closed state can be prevented to some extent. In a non-limiting example, the second threshold may be set to the amount of deformation that the ring-shaped extension apparatus  5  is deformed from the steady state by about 20%, where the maximum amount of deformation of the ring-shaped extension apparatus  5  from the steady state is 100%. 
     A target object T may be knocked down and eliminated when either the left or right object OBJL or OBJR is swung toward the front of the player character PC, or when only a particular one of the left and right objects OBJL and OBJR is swung toward the front of the player character PC. In a first non-limiting example, for each target object T that appears, the characteristic that the target object T can be knocked down using both the left and right objects OBJL and OBJR, the characteristic that the target object T can be knocked down using only the left object OBJL, or the characteristic that the target object T can be knocked down using only the right object OBJR, may be set, and each characteristic may be displayed in a manner that allows the user to view that characteristic. In a second non-limiting example, one or both of the objects OBJL and OBJR that can be used to knock down a target object T may be determined, depending on the location of the target object T. For example, a target object T can be knocked down using both the left and right objects OBJL and OBJR when the target object T approaches the player character PC from the front of the player character PC, a target object T can be knocked down using only the left object OBJL when the target object T approaches the player character PC from the left of the player character PC, and a target object T can be knocked down using only the right object OBJR when the target object T approaches the player character PC from the right of the player character PC. 
     Thus, in the case where a target object T is set that is knocked down and eliminated only when one of the left and right objects OBJL and OBJR is swung toward the front of the player character PC, the direction in which the ring-shaped extension apparatus  5  is swung in order to knock down the target object T is limited. Specifically, the user who operates the ring-shaped extension apparatus  5  as shown in  FIG.  29    is required to not only swing the ring-shaped extension apparatus  5  only in one direction, but also swing the ring-shaped extension apparatus  5  in both directions, depending on the type or location of a target object T. Note that in the case where the direction in which the ring-shaped extension apparatus  5  is swung in order to knock down the target object T is limited, the angle of determination for determining that the ring-shaped extension apparatus  5  has been swung may be set to a different angle for each direction. For example, the angle of determination for determining that the ring-shaped extension apparatus  5  has been swung to a direction (incorrect direction) that a target object T cannot be knocked down may be set to be larger than the angle of determination for determining that the ring-shaped extension apparatus  5  has been swung to a direction (correct direction) that a target object T can be knocked down. In that case, the user&#39;s operation that is not intended by the user, such as the operation of swinging the left and right objects OBJL and OBJR toward an incorrect direction in which a target object T cannot be knocked down, can be reduced. 
     Note that the operation performed using the ring-shaped extension apparatus  5  may be determined using an output from the left controller  3  or another input apparatus in addition to an output from a motion sensor included in the right controller  4  (the ring-shaped extension apparatus  5 ). 
     Although in the foregoing, the operation angle of the ring-shaped extension apparatus  5  is used to detect when the ring-shaped extension apparatus  5  is swung, the determination may be performed using other parameters. For example, the velocity or acceleration at which the ring-shaped extension apparatus  5  is swung to the left or right in the real space may be used, and if such a parameter exceeds a predetermined threshold, it may be determined that the ring-shaped extension apparatus  5  has been swung. 
     Next, a non-limiting example of a specific process that is executed by the game system  1  in the third non-limiting example game will be described with reference to  FIGS.  33 - 36   .  FIG.  33    is a diagram showing a non-limiting example of a data area contained in the DRAM  85  of the main body apparatus  2  in the third non-limiting example game. Note that in addition to the data of  FIG.  33   , the DRAM  85  also stores data that is used in other processes, which will not be described in detail. 
     In the third non-limiting example game, various programs P 1  that are executed in the game system  1  are stored in a program storage area of the DRAM  85 . In this non-limiting example, the programs P 1  include a communication program for performing wireless communication with the right controller  4 , an application program (e.g., a game program) for performing information processing based on data obtained from the right controller  4 , etc. Note that the programs P 1  may be previously stored in the flash memory  84 , may be obtained from a storage medium removably attached to the game system  1  (e.g., a predetermined type of storage medium attached to the slot  23 ) and then stored in the DRAM  85 , or may be obtained from another apparatus via a network, such as the Internet, and then stored in the DRAM  85 . The processor  81  executes the programs P 1  stored in the DRAM  85 . 
     In the third non-limiting example game, various kinds of data that are used in processes such as a communication process and an information process that are executed in the game system  1  are stored in a data storage area of the DRAM  85 . In this non-limiting example, the DRAM  85  stores operation data D 1   a , angular velocity data D 1   b , acceleration data D 1   c , orientation data D 1   d , gravitational direction data D 1   e , ring deformation amount data D 1   g , ring rotational speed data D 1   h , ring rotational angle data D 1   i , swinging action data D 1   j , deformation flag data D 1   k , swing setting flag data D 1   m , swing display flag data D 1   n , score data D 1   p , player character action data D 1   q , target object action data D 1   r , and image data D 1   s , etc. 
     The operation data D 1   a  is obtained from the right controller  4  as appropriate. As described above, the operation data transmitted from the right controller  4  includes information about an input from each input section (specifically, each button, an analog stick, or each sensor) (specifically, information about an operation, and the result of detection by each sensor), and a strain value indicating a state of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5 . In this non-limiting example, operation data is transmitted from the right controller  4  at predetermined time intervals through wireless communication. The received operation data is used to update the operation data D 1   a  as appropriate. Note that the operation data D 1   a  may be updated for each frame that is the cycle of a process executed in the game system  1 , or may be updated each time operation data is received through the wireless communication. 
     The angular velocity data D 1   b  indicates the history of angular velocities occurring on the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The angular velocities are included in the operation data obtained from the right controller  4 . For example, the angular velocity data D 1   b  includes the history of data indicating angular velocities about the x-, y-, and z-axes occurring on the right controller  4 , etc. 
     The acceleration data D 1   c  indicates the history of accelerations occurring on the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The accelerations are included in the operation data obtained from the right controller  4 . For example, the acceleration data D 1   c  includes the history of data indicating accelerations in the x-, y-, and z-axis directions occurring on the right controller  4 , etc. 
     The orientation data D 1   d  indicates an orientation of the right controller  4  in the real space, i.e., data indicating the history of orientations that have occurred during a period of time from the current time to a predetermined time before. In a non-limiting example, the orientation data D 1   d  indicates the history of orientations in the x-, y-, and z-axis directions (e.g., angles with respect to x-, y-, and z-axes in the real space) of the right controller  4  in the real space. 
     The gravitational direction data D 1   e  indicates the direction of a gravitational acceleration acting on the right controller  4 . 
     The ring deformation amount data D 1   g  indicates the direction and amount of deformation of the ring-shaped extension apparatus  5 . The ring rotational speed data D 1   h  indicates a velocity (operation velocity) at which the ring-shaped extension apparatus  5  is swung and turned. The ring rotational angle data D 1   i  indicates an angle (operation angle) by which the ring-shaped extension apparatus  5  is swung and turned. 
     The swinging action data D 1   j  indicates a swinging action that the player character PC is caused to perform, and is set based on an operation performed on the ring-shaped extension apparatus  5 . 
     The deformation flag data D 1   k  indicates a deformation flag that is set “on” when the pressing operation is being performed on the ring-shaped extension apparatus  5 . The swing setting flag data D 1   m  indicates a swing setting flag that is set “on” when a swinging action has been set by an operation performed on the ring-shaped extension apparatus  5 . The swing display flag data D 1   n  indicates a swing display flag that is set “on” when the player character PC is performing a swinging action. 
     The score data D 1   p  indicates the current game score. 
     The player character action data D 1   q  indicates the location, state, orientation, action, etc., of the player character PC disposed in the virtual game space. The target object action data D 1   r  indicates the location, state, orientation, action, etc., of a target object T. 
     The image data D 1   s  is for displaying an image (e.g., an image of the player character PC, an image of a target object T, a field image, a background image, etc.) on a display screen. 
     Next, a specific non-limiting example of an information process in the third non-limiting example game will be described with reference to  FIGS.  34 - 36   .  FIG.  34    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1  in the third non-limiting example game.  FIG.  35    is a subroutine showing a specific non-limiting example of a swing setting process performed in step S 307  shown in  FIG.  34   .  FIG.  36    is a subroutine of a specific non-limiting example of a swing display process performed in step S 311  shown in  FIG.  34   . In the third non-limiting example game, a series of processes shown in  FIGS.  34 - 36    are performed by the processor  81  executing a communication program and a predetermined application program (game program) included in the programs P 1 . The information process of  FIGS.  34 - 36    is started with any suitable timing. 
     Note that the steps in the flowchart of  FIGS.  34 - 36   , which are merely illustrative, may be executed in a different order, or another step may be executed in addition to (or instead of) each step, if a similar effect is obtained. In this non-limiting example, it is assumed that the processor  81  executes each step of the flowchart. Alternatively, a portion of the steps of the flowchart may be executed by a processor or a dedicated circuit other than the processor  81 . In addition, a portion of the steps executed by the main body apparatus  2  may be executed by another information processing apparatus that can communicate with the main body apparatus  2  (e.g., a server that can communicate with the main body apparatus  2  via a network). Specifically, the steps of  FIGS.  34 - 36    may be executed by a plurality of information processing apparatuses including the main body apparatus  2  cooperating with each other. 
     In  FIG.  34   , the processor  81  performs initial setting for the information process (step S 301 ), and proceeds to the next step. For example, in the initial setting, the processor  81  initializes parameters for performing processes to be described below. For example, the processor  81  initially disposes, in the virtual game space, objects (including the player character PC equipped with the objects OBJL and OBJR) to generate an initial state of the virtual game space, and updates the player character action data D 1   q  with the location, direction, state (the closed states of the left and right objects OBJL and OBJR), and orientation, etc., of the player character PC. 
     Next, the processor  81  obtains operation data from the right controller  4  and updates the operation data D 1   a  (step S 302 ), and proceeds to the next step. Note that the processor  81  stores data indicating an angular velocity occurring on the right controller  4 , which is included in the operation data obtained from the right controller  4  in step S 302 , into the angular velocity data D 1   b . The processor  81  also stores data indicating an acceleration occurring on the right controller  4 , which is included in the operation data obtained from the right controller  4  in step S 302 , into the acceleration data D 1   c.    
     Next, the processor  81  calculates the orientation of the right controller  4  (step S 303 ), and proceeds to the next step. For example, the processor  81  obtains the angular velocities about the x-, y-, and z-axes of the right controller  4  using angular velocity data stored in the angular velocity data D 1   b . Thereafter, the processor  81  turns the x-, y-, and z-axes with reference to the gravitational acceleration direction of the orientation of the right controller  4  indicated by the orientation data D 1   d , based on the respective angular velocities obtained, and stores, into the orientation data D 1   d , the directions of the turned x-, y-, and z-axes with reference to the gravitational acceleration direction, as most recent data indicating the orientation of the right controller  4 . The processor  81  also calculates the direction of the gravitational acceleration acting on the right controller  4  using acceleration data stored in the acceleration data D 1   c , and stores the calculated direction into the gravitational direction data D 1   e . Note that the gravitational acceleration may be extracted using any suitable technique. For example, an acceleration component averagely occurring on the right controller  4  may be calculated and extracted as the gravitational acceleration. The processor  81  also corrects, as appropriate, the most recent orientation of the right controller  4  indicated by the orientation data D 1   d  using the direction of the gravitational acceleration occurring on the right controller  4  indicated by the gravitational direction data D 1   e.    
     Next, the processor  81  calculates the amount of deformation of the ring-shaped extension apparatus  5  (step S 304 ), and proceeds to the next step. For example, the processor  81  calculates the amount and direction of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  using a strain value indicated by the operation data D 1   a , and updates the ring deformation amount data D 1   g  with the calculation result. 
     Next, the processor  81  determines whether or not the deformation flag is off (step S 305 ). For example, if the deformation flag indicated by the deformation flag data D 1   k  is off, the result of determination in step S 305  by the processor  81  is positive. If the deformation flag is off, the processor  81  proceeds to step S 306 . Otherwise, i.e., if the deformation flag is on, the processor  81  proceeds to step S 308 . 
     In step S 306 , the processor  81  determines whether or not the amount of deformation calculated in step S 304  is greater than or equal to a first threshold. If the amount of deformation is greater than or equal to the first threshold, the processor  81  proceeds to step S 307 . Otherwise, i.e., if the amount of deformation is smaller than the first threshold, the processor  81  proceeds to step S 310 . Here, the first threshold is used for determining the amount of deformation of the ring-shaped extension apparatus  5  in order to detect when the pressing operation is started on the ring-shaped extension apparatus  5 . If the amount of deformation of the ring-shaped extension apparatus  5  has reached the first threshold or greater, it is determined that a pressing operation has been started. 
     In step S 307 , the processor  81  performs a swing setting process, and proceeds to step S 310 . The swing setting process performed in step S 307  will now be described with reference to  FIG.  35   . 
     In  FIG.  35   , the processor  81  sets the deformation flag “on” (step S 321 ), and proceeds to the next step. For example, the processor  81  sets “on” the deformation flag indicated by the deformation flag data D 1   k  to update the deformation flag data D 1   k.    
     Next, the processor  81  determines whether or not the swing setting flag is off (step S 322 ). For example, if the swing setting flag indicated by the swing setting flag data D 1   m  is off, the result of determination in step S 322  by the processor  81  is positive. If the swing setting flag is off, the processor  81  proceeds to step S 323 . Otherwise, i.e., if the swing setting flag is on, the processor  81  ends the process of the subroutine. 
     In step S 323 , the processor  81  calculates a velocity (operation velocity) at which the ring-shaped extension apparatus  5  has been swung and turned in the real space, and proceeds to the next step. For example, the processor  81  calculates the operation velocity with reference to the acceleration data D 1   c , and updates the ring rotational speed data D 1   h . Note that the operation velocity may be a velocity at which the ring-shaped extension apparatus  5  (the right controller  4 ) is moved in a horizontal direction in the real space, and is calculated based on the most recent orientation indicated by the orientation data D 1   d , or a velocity at which the ring-shaped extension apparatus  5  (the right controller  4 ) is moved in a direction perpendicular to the circular-ring axis of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  (i.e., a direction perpendicular to the z-axis direction of the right controller  4 ). 
     Next, the processor  81  calculates an angle (operation angle) and operation direction in which the ring-shaped extension apparatus  5  has been swung and turned in the real space, and proceeds to the next step. For example, with reference to the angular velocity data D 1   c  and the orientation data D 1   d , the processor  81  calculates an angle of the ring-shaped extension apparatus  5  turned from a reference orientation, as the operation angle, and updates the ring rotational angle data D 1   i  with the operation angle and operation direction, where the reference operation is the orientation of the ring-shaped extension apparatus  5  at the time that the deformation flag is changed from off to on. Note that the operation angle may be an angle by which the ring-shaped extension apparatus  5  (the right controller  4 ) in the reference orientation is turned around the vertically downward direction of the real space, or an angle by which the ring-shaped extension apparatus  5  (the right controller  4 ) is turned around the circular-ring axis of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  (i.e., around the z-axis direction of the right controller  4 ). 
     Next, the processor  81  sets a correct direction/incorrect direction (step S 325 ), and proceeds to the next step. Here, as described above, the correct direction is such that a target object T can be knocked down by the left or right object OBJL or OBJR, and the incorrect direction is such that a target object T cannot be knocked down by the left or right object OBJL or OBJR. The processor  81  sets the correct direction/incorrect direction based on the type of a target object T that is currently located closest to the player character PC in the virtual game space. 
     Next, the processor  81  determines whether or not a direction in which the left or right object OBJL or OBJR has been swung in the virtual game space according to the operation direction calculated in step S 324  is a correct direction (step S 326 ). If the swinging direction is a correct direction, the processor  81  proceeds to step S 327 . Otherwise, i.e., if the swinging direction is an incorrect direction, the processor  81  proceeds to step S 329 . Note that if the correct direction/incorrect direction has not been set in step S 325  or if the operation direction has not been calculated in step S 324  (i.e., the operation angle is zero), the result of determination in step S 326  by the processor  81  is positive. 
     In step S 327 , the processor  81  determines whether or not the operation angle calculated in step S 324  is greater than or equal to a third threshold. If the operation angle is greater than or equal to the third threshold, the processor  81  proceeds to step S 328 . Otherwise, i.e., if the operation angle is smaller than the third threshold, the processor  81  ends the process of the subroutine. Here, the third threshold is for determining the operation angle of the ring-shaped extension apparatus  5  in order to detect when the ring-shaped extension apparatus  5  is swung in a correct direction, and is set to, for example, 45 degrees. When the operation angle of the ring-shaped extension apparatus  5  in a correct direction has reached the third threshold or greater, it is determined that the operation of swinging the ring-shaped extension apparatus  5  in a correct direction has been performed. 
     In step S 328 , the processor  81  sets a swinging action in a correct direction for the player character PC, and proceeds to step S 331 . For example, the processor  81  sets an action of swinging the left and right objects OBJL and OBJR so that the player character PC swings the left or right object OBJL or OBJR in a correct direction at a predetermined velocity to a predetermined angle, and updates the swinging action data D 1   j  using the set action. Note that the swinging action may be set so that the swinging velocity is increased with an increase in the operation velocity calculated in step S 323 . 
     Meanwhile, in step S 329 , the processor  81  determines whether or not the operation angle calculated in step S 324  is greater than or equal to a fourth threshold. If the operation angle is greater than or equal to the fourth threshold, the processor  81  proceeds to step S 330 . Otherwise, i.e., if the operation angle is smaller than the fourth threshold, the processor  81  ends the process of the subroutine. Here, the fourth threshold is for determining the operation angle of the ring-shaped extension apparatus  5  in order to detect when the ring-shaped extension apparatus  5  is swung in an incorrect direction, and may be set to a value (e.g., 60 degrees) greater than the third threshold. 
     In step S 330 , the processor  81  sets a swinging action in an incorrect direction for the player character PC, and proceeds to step S 331 . For example, the processor  81  sets an action of swinging the left and right objects OBJL and OBJR so that the player character PC swings the left or right object OBJL or OBJR in an incorrect direction at a predetermined velocity to a predetermined angle, and updates the swinging action data D 1   j  with the set action. 
     In step S 331 , the processor  81  sets the swing display flag “on,” and proceeds to the next step. For example, the processor  81  sets “on” the swing display flag indicated by the swing display flag data D 1   n  to update the swing display flag data D 1   n.    
     Next, the processor  81  sets the swing setting flag “on” (step S 332 ), and ends the process of the subroutine. For example, the processor  81  sets “on” the swing setting flag indicated by the swing setting flag data D 1   m  to update the swing setting flag data D 1   m . Thus, when a swinging action in a correct or incorrect direction is set according to an operation performed on the ring-shaped extension apparatus  5 , the swing setting flag is set “on,” and therefore, even when the pressing operation performed on the ring-shaped extension apparatus  5  is continued after the swinging action is set, the result of determination in step S 322  is negative, and a new swinging action is not set. 
     Referring back to  FIG.  34   , if it is determined in step S 305  that the deformation flag is on, the processor  81  determines whether or not the amount of deformation calculated in step S 308  is greater than or equal to a second threshold. If the amount of deformation is greater than or equal to the second threshold, the processor  81  proceeds to step S 307 . Otherwise, i.e., if the amount of deformation is smaller than the second threshold, the processor  81  proceeds to step S 309 . Here, the second threshold is for determining that the pressing operation on the ring-shaped extension apparatus  5  is continued even when the force applied to the ring-shaped extension apparatus  5  is reduced after the start of the pressing operation, and is set to be smaller than the first threshold. 
     In step S 309 , the processor  81  sets “off” the deformation flag and the swing setting flag, and proceeds to step S 310 . For example, the processor  81  sets “off” each of the deformation flag indicated by the deformation flag data D 1   k  and the swing setting flag indicated by the swing setting flag data D 1   m  to update each of the deformation flag data D 1   k  and the swing setting flag data D 1   m . Thus, when the pressing operation performed on the ring-shaped extension apparatus  5  is reduced to the amount of deformation that is smaller than the second threshold, it is determined that the pressing operation has been stopped, and sets the deformation flag “off” and the swing setting flag “off,” and therefore, a new swinging action can be set. 
     In step S 310 , the processor  81  determines whether or not the swing display flag is on. For example, if the swing display flag indicated by the swing display flag data D 1   n  is on, the result of determination in step S 310  by the processor  81  is positive. If the swing display flag is on, the processor  81  proceeds to step S 311 . Otherwise, i.e., if the swing display flag is off, the processor  81  proceeds to step S 312 . 
     In step S 311 , the processor  81  performs a swing display process, and proceeds to step S 312 . The swing display process performed in step S 311  will now be described with reference to  FIG.  36   . 
     In  FIG.  36   , the processor  81  sets a swing state of the player character PC (step S 341 ), and proceeds to the next step. For example, the processor  81  sets a current orientation in which the player character PC swings the left and right objects OBJL and OBJR (e.g., current angles at which the left and right objects OBJL and OBJR are swung or a current orientation of the player character PC), based on a swinging action indicated by the swinging action data D 1   j , to update the player character action data D 1   q.    
     Next, the processor  81  determines whether or not the player character PC&#39;s attack against a target object T is successful (step S 342 ). For example, if the swing state set in step S 341  indicates collision with a target object T, and also indicates that the player character PC swings the left and right objects OBJL and OBJR in a correct direction, the processor  81  determines that the attack against the target object T is successful. If the player character PC&#39;s attack against the target object T is successful, the processor  81  proceeds to step S 343 . Otherwise, i.e., if the player character PC&#39;s attack against the target object T is unsuccessful, the processor  81  proceeds to step S 345 . 
     In step S 343 , the processor  81  calculates game points based on a velocity parameter, and proceeds to the next step. For example, the processor  81  calculates game points for the successful attack against the target object T, based on attack power depending on a velocity parameter (a velocity, acceleration, angular velocity, etc.) acting on the ring-shaped extension apparatus  5  at the start of swinging, and updates the score data D 1   p  by adding the game points. Specifically, the processor  81  may calculate game points based on an acceleration or angular velocity at which the ring-shaped extension apparatus  5  is swung to the left or right, a velocity indicated by the ring rotational speed data D 1   h , etc., at the start of swinging. In a non-limiting example, the velocity parameter may be rated on a scale including several levels, and the game parameter may be calculated based on the levels. Note that a predetermined number of game points may be obtained for a successful attack against a target object T. In that case, game points are added irrespective of the velocity parameter. 
     Next, the processor  81  sets a state of the attacked target object T (step S 344 ), and proceeds to step S 347 . For example, the processor  81  sets a state in which the attacked target object T is knocked down by the attack, and displays a scene that the target object T disappears from the virtual game space, and updates the target object action data D 1   r  based on the scene. 
     Meanwhile, if it is determined in step S 342  that the attack against the target object T is unsuccessful, the processor  81  determines whether or not the player character PC&#39;s unsuccessful attack against the target object T has been finally determined as a failure (step S 345 ). For example, if the swing state determined in step S 341  indicates collision with the target object T, and also indicates that the player character PC swings the left and right objects OBJL and OBJR in an incorrect direction, or if the swing state determined in step S 341  indicates the player character PC swings the left and right objects OBJL and OBJR all the way down without collision with the target object T, the processor  81  determines that the attack against the target object T has been finally determined as a failure. If the player character PC&#39;s unsuccessful attack against the target object T has been finally determined as a failure, the processor  81  proceeds to step S 346 . Otherwise, i.e., if the player character PC&#39;s unsuccessful attack against the target object T has not been finally determined as a failure, the processor  81  proceeds to step S 348 . 
     In step S 346 , the processor  81  sets a state of the target object T for which the attack has been determined as a failure (step S 346 ), and proceeds to step S 347 . For example, the processor  81  displays a scene that the target object T for which the attack has been determined a failure has won against the player character PC, and thereafter, displays a scene that the target object T disappears from the virtual game space, and updates the target object action data D 1   r  based on the scenes. 
     In step S 347 , the processor  81  sets the swing display flag “off,” and proceeds to step S 348 . For example, the processor  81  sets “off” the swing display flag indicated by the swing display flag data D 1   n  to update the swing display flag data D 1   n.    
     In step S 348 , the processor  81  determines whether or not the amount of deformation calculated in step S 304  is smaller than the second threshold. If the amount of deformation is smaller than the second threshold, the processor  81  proceeds to step S 349 . Otherwise, i.e., if the amount of deformation is greater than or equal to the second threshold, the processor  81  ends the process of the subroutine. 
     In step S 349 , the processor  81  sets “off” the deformation flag and the swing setting flag, and ends the process of the subroutine. For example, the processor  81  sets “off” each of the deformation flag indicated by the deformation flag data D 1   k  and the swing setting flag indicated by the swing setting flag data D 1   m  to update each of the deformation flag data D 1   k  and the swing setting flag data D 1   m . Thus, even during the swing display process, i.e., even when a scene that the player character PC is swinging the left and right objects OBJL and OBJR is being displayed, then if a pressing operation performed on the ring-shaped extension apparatus  5  is reduced, so that the amount of deformation is smaller than the second threshold, it is determined that the pressing operation has been stopped, and the deformation flag is set “off” If the swing setting flag is thus set “off,” a new swinging action can be set. Note that there may be a limitation on the process of changing the deformation flag and the swing setting flag to “off” during swing display. For example, the number of times the process of changing the deformation flag and the swing setting flag to “off” during single swing display, may limited to once or less. 
     Referring back to  FIG.  34   , in step S 312 , the processor  81  performs the process of controlling the action of an object (the player character PC, a target object T, etc.), and proceeds to the next step. For example, the processor  81  disposes the player character PC in the virtual game space based on the location, state, orientation, action, etc., of the player character PC indicated by the player character action data D 1   q . The processor  81  also causes a target object T to appear in the virtual game space and move toward the player character PC, based on a predetermined algorithm (appearance pattern), and updates the target object action data D 1   r  based on the location after the appearance and movement. 
     Next, the processor  81  performs an image generation and display control process (step S 313 ), and proceeds to the next step. For example, the processor  81  disposes a plurality of objects (the player character PC equipped with the object OBJL and OBJR, a target object T, etc.) in the virtual game space based on the settings provided by steps S 311  and S 312 , to generate the virtual game space. The processor  81  also disposes a virtual camera in the virtual game space, generates an image of the virtual game space as viewed from the virtual camera, and outputs the virtual game space image to the stationary monitor  9 . The processor  81  also causes an image indicating the game score indicated by the score data D 1   p  to overlay the virtual game space image at an appropriate position, and outputs the resultant image to the stationary monitor  9 . 
     Next, the processor  81  determines whether or not to end the game process (step S 314 ). In step S 314 , a condition for ending the game process is, for example, that a condition for ending the game process is satisfied, that the user has performed an operation of ending the game process, etc. If the processor  81  determines not to end the game process, the processor  81  returns to step S 302 , and repeats the process. Otherwise, i.e., if the processor  81  determines to end the game process, the processor  81  ends the process of the flowchart. Thereafter, steps S 302 -S 314  are repeatedly executed until the processor  81  determines to end the game process in step S 314 . 
     Thus, in the third non-limiting example game, a predetermined game process is performed by swinging the ring-shaped extension apparatus  5  while deforming the ring-shaped extension apparatus  5 , resulting in an improvement in the user&#39;s bodily sensation in an operation using the ring-shaped extension apparatus  5 . In addition, in the third non-limiting example game, when the ring-shaped extension apparatus  5  is not deformed, or when the ring-shaped extension apparatus  5  is deformed and is not swung, the execution of a predetermined game process is limited, and therefore, the predetermined game process is limited by the user&#39;s particular operation. 
     Note that in the third non-limiting example game, the user&#39;s operation is performed using the ring-shaped extension apparatus  5 . Alternatively, as in the first and second non-limiting example games, the user&#39;s operation may be performed using the ring-shaped extension apparatus  5  as well as the belt-shaped extension apparatus  6  with the left controller  3  attached thereto. In that case, the process using the output of the motion sensor (the acceleration sensor  114  and/or the angular velocity sensor  115  of the right controller  4 ) of the ring-shaped extension apparatus  5  may be replaced by a process using the output of the motion sensor (the acceleration sensor  104  and/or the angular velocity sensor  105  of the left controller  3 ) of the belt-shaped extension apparatus  6 . Thus, the user&#39;s operation is also performed using the belt-shaped extension apparatus  6  with the left controller  3  attached thereto, and therefore, in the third non-limiting example game, the control of switching between the action mode in which the player character PC is allowed to attach a target object T and the action mode in which the player character PC is not allowed to attach a target object T, and the control of changing the states of the left and right objects OBJL and OBJR, are performed according to a pressing operation of deforming the ring-shaped extension apparatus  5 , and the action control of swinging the left and right objects OBJL and OBJR to the left and right is performed according to the motion of the belt-shaped extension apparatus  6  caused by the motion of the user&#39;s leg. Therefore, the variety of user inputs using both of the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6  can be increased. 
     Fourth Non-Limiting Example Game 
     Next, before describing a specific process in a fourth non-limiting example game performed by the main body apparatus  2 , the fourth non-limiting example game performed in the main body apparatus  2  will be outlined with reference to  FIGS.  37 - 40   . Note that  FIG.  37    is a diagram showing a non-limiting example of how, in the fourth non-limiting example game, the user operates the ring-shaped extension apparatus  5 .  FIG.  38    is a diagram showing a first non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the fourth non-limiting example game.  FIG.  39    is a diagram showing a second non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the fourth non-limiting example game.  FIG.  40    is a diagram showing a third non-limiting example of a game image displayed on the stationary monitor  9  according to the user&#39;s operation in the fourth non-limiting example game. 
     As shown in  FIG.  37   , in the fourth non-limiting example game, the user holds both of the grip covers  203  and  204  of the ring-shaped extension apparatus  5  using both hands (each grip cover is held by one hand), and in this state, performs an operation of moving and swinging down the ring-shaped extension apparatus  5  from above to near the user&#39;s abdomen while deforming the ring-shaped extension apparatus  5  using both hands so that the two grip covers  203  and  204  of the ring-shaped extension apparatus  5  move toward each other. Here, in order to swinging down the ring-shaped extension apparatus  5  from above while deforming the ring-shaped extension apparatus  5  so that the two grip covers  203  and  204  move toward each other, the user performs an action similar to a motion of the upper body occurring when the user jumps while applying a force to both hands, i.e., the user is required to perform a gaming operation imitating jumping. 
     In the fourth non-limiting example game, the game system will be described, assuming the situation that the left controller  3  and the right controller  4  are removed from the main body apparatus  2 , and the main body apparatus  2  alone is attached to the cradle  8 , and an image (and sound) is output from the stationary monitor  9  connected to the cradle  8 . In a non-limiting example, the user performs a gaming operation using the right controller  4  attached to the ring-shaped extension apparatus  5 . In a non-limiting example of a game process in the fourth non-limiting example game, a process is used in which a player character PC displayed on the stationary monitor  9  moves (jump) in the virtual game space according to the user&#39;s operation. 
     For example, in  FIG.  38   , the player character PC is disposed in the virtual game space. The player character PC is disposed along a wall extending upward in the virtual game space. As shown in  FIG.  38   , when the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is in the steady state in which the ring-shaped portion  201  is not deformed, the player character PC is not moving along the wall. 
     Meanwhile, as shown in  FIG.  39   , when the user performs an operation of deforming the ring-shaped extension apparatus  5  so that the ring-shaped portion  201  is changed from the steady state to at least a predetermined state and thereby the grip covers  203  and  204  move toward each other (a pressing operation of deforming the ring-shaped portion  201  in a B direction shown in  FIG.  22   ), a label M indicating a height that the player character PC can reach when jumping and moving, is displayed above the player character PC along the wall. Such a pressing operation is detected based on a strain detected by the strain gauge included in the ring-shaped extension apparatus  5  as in the third non-limiting example game. In addition, when the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is deformed from the steady state, a strain of the base portion is detected by the strain gauge, and based on the detected strain, a direction in which the ring-shaped portion  201  is deformed (i.e., a direction in which the two grip covers  203  and  204  move away from each other, or a direction in which the two grip covers  203  and  204  move toward each other), and the amount of deformation, can be calculated. If the ring-shaped portion  201  is deformed in the direction in which the two grip covers  203  and  204  move toward each other, the label M indicating a reachable height corresponding to the calculated amount of deformation is displayed. When the pressing operation is stopped, a scene is displayed that the reachable height indicated by the label M gradually decreases, and the label M finally disappears. Note that the label M corresponds to a non-limiting example of an image indicating the amount of deformation of the first input apparatus. 
     As shown in  FIG.  40   , when an operation of swinging the ring-shaped extension apparatus  5  downward (D direction in  FIG.  23   ) in the real space is performed together with the pressing operation, the player character PC performs an action of jumping along the wall to try to reach the reachable height indicated by the label M immediately before the swinging operation. Here, the operation of swinging the ring-shaped extension apparatus  5  downward is a pitch operation that causes the ring-shaped extension apparatus  5  to move in a vertically downward direction in the real space with the pressing operation applied to the ring-shaped extension apparatus  5 . When the operation of swinging the ring-shaped extension apparatus  5  downward is performed together with the pressing operation, the player character PC performs an action of moving in the virtual game space, i.e., jump along the wall. A predetermined number of game points can be given to the user based on the location that the player character PC has reached. Specifically, if the player character PC jumps too high, no game points may not be obtained, and therefore, the user is required to cause the player character PC to jump using an appropriate level of jump power. 
     Thus, when the pitch operation of swinging the ring-shaped extension apparatus  5  downward is performed, an acceleration downward in the real space and an angular velocity around the y-axis direction (see  FIG.  6   ) occur on the right controller  4  attached to the ring-shaped extension apparatus  5 . Therefore, an acceleration detected by the acceleration sensor  114  of the right controller  4  and/or an angular velocity detected by the angular velocity sensor  115  of the right controller  4  can be used to calculate the operation direction, operation angle, and operation velocity, etc., of the pitch operation of swinging the ring-shaped extension apparatus  5  downward. In the fourth non-limiting example game, when the pitch operation of swinging the ring-shaped extension apparatus  5  downward is performed together with the pressing operation, the process of causing the player character PC to jump and move to a reachable height depending on the amount of deformation caused by the pressing operation is performed. Actually, the pitch operation of swinging the ring-shaped extension apparatus  5  downward may be accompanied by a roll operation or yaw operation of the ring-shaped extension apparatus  5 . Therefore, the presence or absence of a final pitch operation of swinging downward may be determined by combining changes in respective directions of the ring-shaped extension apparatus  5  by the roll operation, pitch operation, and yaw operation. 
     Note that the operation of causing the player character PC to jump and move may be allowed only once for each pressing operation. In a non-limiting example, after the player character PC has jumped and moved, the label M may no longer be displayed even when the pressing operation is continued. In that case, the user is required to perform a pressing operation again after returning the ring-shaped portion  201  of the ring-shaped extension apparatus  5  to the steady state, and perform an operation of swinging and moving the ring-shaped extension apparatus  5 , in order to cause the label M to be displayed again, and cause the player character PC to jump and move again. 
     In the pitch operation of swinging the ring-shaped extension apparatus  5  downward together with the pressing operation, the force for performing the pressing operation may be reduced by the pitch operation. In that case, the player character PC may fail to jump to the reachable height indicated by the label M displayed before the pitch operation. In order to prevent such an unintended reduction in jump power due to the reduction of the force for performing the pressing operation, the reachable height for the player character PC may be calculated based on the amount of deformation of the ring-shaped extension apparatus  5  that has occurred a predetermined time (e.g., five frames) before the pitch operation, or the greatest amount of deformation of the ring-shaped extension apparatus  5  that has occurred during a period of time from the current time to a predetermined time before. 
     When the pitch operation of swinging the ring-shaped extension apparatus  5  downward is performed without the pressing operation, jump power may not be calculated, and therefore, a scene that the player character PC does not jump may be displayed. In that case, game points that could be obtained by causing the player character PC to jump are not obtained, and the degree of game achievement cannot be updated. Therefore, when the pitch operation of swinging the ring-shaped extension apparatus  5  downward is performed without the pressing operation performed on the ring-shaped extension apparatus  5 , in a non-limiting example the user may be prompted to perform an operation of deforming the ring-shaped extension apparatus  5 , by providing to the user a predetermined image or sound (e.g., a text image “press the ring-shaped extension apparatus  5 ” or a voice “press the ring-shaped extension apparatus  5 ”). 
     The jump power by which the player character PC is caused to jump may be determined based on another parameter in addition to the amount of deformation of the ring-shaped extension apparatus  5 . For example, the jump power may be calculated using both a velocity parameter (a velocity, acceleration, angular velocity, etc.) at which the ring-shaped extension apparatus  5  is swung downward during jumping, and the amount of deformation. 
     When the user operates the ring-shaped extension apparatus  5  with the ring-shaped extension apparatus  5  held in an incorrect orientation, the scene that the player character PC jumps may not be displayed even when the operation of swinging the ring-shaped extension apparatus  5  downward is performed while deforming the ring-shaped extension apparatus  5 . Here, as shown in  FIG.  37   , the correct orientation of the ring-shaped extension apparatus  5  when held is such that the user holds the grip covers  203  and  204  with both hands, with the right controller  4  located at a highest position and the two grip covers  203  and  204  aligned substantially horizontally; the pressing operation and the downward-swinging operation are performed on the ring-shaped extension apparatus  5  with the circular-ring axis of the ring-shaped portion  201  pointing in substantially the horizontal direction, i.e., in substantially the horizontal position. The determination of whether or not an operation has been performed in such a correct orientation can be achieved by analyzing the orientation of the ring-shaped extension apparatus  5  at the time that it is determined that the ring-shaped extension apparatus  5  has been swung downward. 
     Next, a non-limiting example of a specific process that is executed by the game system  1  in the fourth non-limiting example game will be described with reference to  FIGS.  41 - 43   .  FIG.  41    is a diagram showing a non-limiting example of a data area contained in the DRAM  85  of the main body apparatus  2  in the fourth non-limiting example game. Note that the DRAM  85  stores, in addition to the data shown in  FIG.  41   , data used in other processes, which will not be described in detail. 
     In the fourth non-limiting example game, various programs P 2  that are executed in the game system  1  are stored in a program storage area of the DRAM  85 . In this non-limiting example, the programs P 2  include a communication program for performing wireless communication with the right controller  4 , an application program (e.g., a game program) for performing information processing based on data obtained from the right controller  4 , etc. Note that the programs P 2  may be previously stored in the flash memory  84 , may be obtained from a storage medium removably attached to the game system  1  (e.g., a predetermined type of storage medium attached to the slot  23 ) and then stored in the DRAM  85 , or may be obtained from another apparatus via a network, such as the Internet, and then stored in the DRAM  85 . The processor  81  executes the programs P 2  stored in the DRAM  85 . 
     In the fourth non-limiting example game, various kinds of data that are used in processes such as communication processing and information processing that are executed in the game system  1  are stored in a data storage area of the DRAM  85 . In this non-limiting example, the DRAM  85  stores operation data D 2   a , angular velocity data D 2   b , acceleration data D 2   c , orientation data D 2   d , gravitational direction data D 2   e , ring deformation amount data D 2   g , jump power data D 2   h , jump flag data D 2   i , score data D 2   j , player character action data D 2   k , and image data D 2   m , etc. 
     The operation data D 2   a  is data indicating an operation that is obtained from the right controller  4  as appropriate. As described above, the operation data transmitted from the right controller  4  includes information about an input from each input section (specifically, each button, an analog stick, and each sensor) (specifically, information about an operation, and the result of detection by each sensor), and a strain value indicating the state of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5 . In this non-limiting example, operation data is transmitted from the right controller  4  at predetermined time intervals through wireless communication. The received operation data is used to update the operation data D 2   a  as appropriate. Note that the operation data D 2   a  may be updated for each frame that is the cycle of a process executed in the game system  1 , or may be updated each time operation data is received through the wireless communication. 
     The angular velocity data D 2   b  indicates the history of angular velocities occurring on the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The angular velocities are included in the operation data obtained from the right controller  4 . For example, the angular velocity data D 2   b  includes the history of data indicating angular velocities about the x-, y-, and z-axes occurring on the right controller  4 , etc. 
     The acceleration data D 2   c  indicates the history of accelerations occurring on the right controller  4  that have been obtained during a period of time from the current time to a predetermined time before. The accelerations are included in the operation data obtained from the right controller  4 . For example, the acceleration data D 2   c  includes the history of data indicating accelerations in the x-, y-, and z-axis directions occurring on the right controller  4 , etc. 
     The orientation data D 2   d  indicates an orientation of the right controller  4  in the real space, i.e., data indicating the history of orientations that have occurred during a period of time from the current time to a predetermined time before. In a non-limiting example, the orientation data D 2   d  indicates the history of orientations in the x-, y-, and z-axis directions (e.g., angles with respect to x-, y-, and z-axes in the real space) of the right controller  4  in the real space. 
     The gravitational direction data D 2   e  indicates the direction of a gravitational acceleration acting on the right controller  4 . 
     The ring deformation amount data D 2   g  indicates the history of the directions and amounts of deformation of the ring-shaped extension apparatus  5  that have been calculated during a period of time from the current time to a predetermined time before. 
     The jump power data D 2   h  indicates jump power for causing the player character PC to move, which is set according to an operation performed on the ring-shaped extension apparatus  5 . 
     The jump flag data D 2   i  indicates a jump flag that is set “on” when the scene that the player character PC jumps is displayed. 
     The score data D 2   j  indicates the current game score. 
     The player character action data D 2   k  indicates the location, state, orientation, action, etc., of the player character PC disposed in the virtual game space. 
     The image data D 2   m  is for displaying an image (e.g., an image of the player character PC, a field image, a background image, etc.) on a display screen. 
     Next, a specific non-limiting example of information processing in the fourth non-limiting example game will be described with reference to  FIGS.  42  and  43   .  FIG.  42    is a flowchart showing a non-limiting example of an information process that is executed by the game system  1  in the fourth non-limiting example game.  FIG.  43    is a subroutine showing a specific non-limiting example of a jump display process performed in step S 410  shown in  FIG.  42   . In the fourth non-limiting example game, a series of processes shown in  FIGS.  42  and  43    are performed by the processor  81  executing a communication program and a predetermined application program (game program) included in the programs P 2 . The information processing of  FIGS.  42  and  43    is started with any suitable timing. 
     Note that the steps in the flowchart of  FIGS.  42  and  43   , which are merely illustrative, may be executed in a different order, or another step may be executed in addition to (or instead of) each step, if a similar effect is obtained. In this non-limiting example, it is assumed that the processor  81  executes each step of the flowchart. Alternatively, a portion of the steps of the flowchart may be executed by a processor or a dedicated circuit other than the processor  81 . In addition, a portion of the steps executed by the main body apparatus  2  may be executed by another information processing apparatus that can communicate with the main body apparatus  2  (e.g., a server that can communicate with the main body apparatus  2  via a network). Specifically, the steps of  FIGS.  42  and  43    may be executed by a plurality of information processing apparatuses including the main body apparatus  2  cooperating with each other. 
     In  FIG.  42   , the processor  81  performs initial setting for information processing (step S 401 ), and proceeds to the next step. For example, in the initial setting, the processor  81  initializes parameters for performing processes to be described below. For example, the processor  81  initially disposes the player character PC in the virtual game space to generate an initial state of the virtual game space, and updates the player character action data D 2   k  with the location, direction, state, and orientation, etc., of the player character PC. 
     Next, the processor  81  obtains the operation data from the right controller  4  and updates the operation data D 2   a  (step S 402 ), and proceeds to the next step. Note that the processor  81  stores data indicating an angular velocity occurring on the right controller  4 , which is included in the operation data obtained from the right controller  4  in step S 402 , into the angular velocity data D 2   b . The processor  81  also stores data indicating an acceleration occurring on the right controller  4 , which is included in the operation data obtained from the right controller  4  in step S 402 , into the acceleration data D 2   c.    
     Next, the processor  81  calculates the orientation of the right controller  4  (step S 403 ), and proceeds to the next step. For example, the processor  81  obtains the angular velocities about the x-, y-, and z-axes of the right controller  4  using the angular velocity data stored in the angular velocity data D 2   b . Thereafter, the processor  81  turns the x-, y-, and z-axes with reference to the gravitational acceleration direction of the orientation of the right controller  4  indicated by the orientation data D 2   d , based on the obtained angular velocities, and stores, into the orientation data D 2   d , the directions of the turned x-, y-, and z-axes with reference to the gravitational acceleration direction, as most recent data indicating the orientation of the right controller  4 . The processor  81  also calculates the direction of the gravitational acceleration acting on the right controller  4  using the acceleration data stored in the acceleration data D 2   c , and stores the calculated direction into the gravitational direction data D 2   e . Note that the gravitational acceleration may be extracted using any suitable technique. For example, an acceleration component averagely occurring on the right controller  4  may be calculated and extracted as the gravitational acceleration. The processor  81  also corrects, as appropriate, the most recent orientation of the right controller  4  indicated by the orientation data D 2   d  using the direction of the gravitational acceleration occurring on the right controller  4  indicated by the gravitational direction data D 2   e.    
     Next, the processor  81  calculates the amount of deformation of the ring-shaped extension apparatus  5  (step S 404 ), and proceeds to the next step. For example, the processor  81  calculates the amount and direction of deformation of the ring-shaped portion  201  of the ring-shaped extension apparatus  5  using the strain value indicated by the operation data D 2   a , and adds the calculation result to the history of the amounts of deformation indicated by the ring deformation amount data D 2   g.    
     Next, the processor  81  determines whether or not the jump flag is off (step S 405 ). For example, if the jump flag indicated by the jump flag data D 2   i  is off, the result of determination in step S 405  by the processor  81  is positive. If the jump flag is off, the processor  81  proceeds to step S 406 . Otherwise, i.e., if the jump flag is on, the processor  81  proceeds to step S 408 . 
     In step S 406 , the processor  81  calculates jump power based on the amount of deformation calculated in step S 404 , and proceeds to the next step. For example, the processor  81  calculates jump power based on the most recent amount of deformation in the history of the amounts of deformation indicated by the ring deformation amount data D 2   g , and updates the jump power data D 2   h  with the jump power. 
     Next, the processor  81  sets the label M corresponding to a predicted reach height which depends on the jump power calculated in step S 406  (step S 407 ), and proceeds to step S 408 . For example, the processor  81  calculates a height that the player character PC can reach when the player character PC jumps with the jump power indicated by the jump power data D 2   h , and sets the label M corresponding to the reachable height. 
     In step S 408 , the processor  81  calculates a velocity parameter (e.g., an acceleration, velocity, angular velocity) at which the ring-shaped extension apparatus  5  is moved downward in the real space, and proceeds to the next step. For example, the processor  81  calculates an acceleration, velocity, or angular velocity at which the ring-shaped extension apparatus  5  is moved downward in the real space as a velocity parameter, with reference to the acceleration data D 2   c . In a first non-limiting example, the velocity parameter may be an acceleration or velocity at which the ring-shaped extension apparatus  5  (the right controller  4 ) is moved downward in the real space, or an angular velocity at which a pitch operation around the horizontal direction is performed on the ring-shaped extension apparatus  5 . These parameters are calculated based on the most recent orientation indicated by the orientation data D 2   d . In a second non-limiting example, the velocity parameter may be an acceleration or velocity at which the ring-shaped extension apparatus  5  is moved in a direction from the right controller  4  toward the circular-ring axis of the ring-shaped portion  201  (i.e., a direction perpendicular to the z-axis direction of the right controller  4  (the negative direction of the x-axis)), or an angular velocity at which a pitch operation is performed (i.e., an operation of turning the right controller  4  around the y-axis direction). 
     Next, the processor  81  determines whether or not to display a scene that the player character PC jumps (step S 409 ). For example, if the velocity parameter calculated in step S 408  is greater than or equal to a predetermined threshold for determining that the operation of swinging the ring-shaped extension apparatus  5  downward has been started, the result of determination in step S 409  by the processor  81  is positive. If the jump flag indicated by the jump flag data D 2   i  is on, the result of determination in step S 409  by the processor  81  is positive. If the result of determination in step S 409  by the processor  81  is positive, the processor  81  proceeds to step S 410 . Otherwise, i.e., if the result of determination in step S 409  by the processor  81  is negative, the processor  81  proceeds to step S 411 . 
     Note that when it is determined that the user has operated the ring-shaped extension apparatus  5  with the ring-shaped extension apparatus  5  held in an incorrect orientation, the result of determination in step S 409  may be negative. Here, as shown in  FIG.  37   , the correct orientation of the ring-shaped extension apparatus  5  when held is such that the user holds the grip covers  203  and  204  with both hands, with the right controller  4  located at a highest position and the two grip covers  203  and  204  aligned substantially horizontally; the pressing operation and the downward-swinging operation are performed on the ring-shaped extension apparatus  5  with the circular-ring axis of the ring-shaped portion  201  in substantially the horizontal position. The determination of whether or not an operation has been performed in such a correct orientation can be achieved by analyzing the orientation of the ring-shaped extension apparatus  5  indicated by the orientation data D 2   d.    
     In step S 410 , the processor  81  performs a jump display process, and proceeds to step S 411 . The jump display process performed in step S 410  will now be described with reference to  FIG.  43   . 
     In  FIG.  43   , the processor  81  determines whether or not the jump flag indicated by the jump flag data D 2   i  is off (step S 420 ). If the jump flag is off, the processor  81  proceeds to step S 421 . Otherwise, i.e., if the jump flag is on, the processor  81  proceeds to step S 424 . 
     In step S 421 , the processor  81  sets the jump flag “on,” and proceeds to the next step. For example, the processor  81  sets “on” the jump flag indicated by the jump flag data D 2   i  to update the jump flag data D 2   i . The processor  81  also removes the setting of the label M set in step S 407 . 
     Next, the processor  81  determines whether or not the amount of deformation of the ring-shaped extension apparatus  5  has gradually decreased (step S 422 ). For example, the processor  81  determines whether or not the amount of deformation has gradually decreased, with reference to the history of the amounts of deformation indicated by the ring deformation amount data D 2   g . If the amount of deformation of the ring-shaped extension apparatus  5  has gradually decreased, the processor  81  proceeds to step S 423 . Otherwise, i.e., if the amount of deformation of the ring-shaped extension apparatus  5  has not gradually decreased, the processor  81  proceeds to step S 424 . 
     In step S 423 , the processor  81  newly calculates jump power using the amount of deformation of the ring-shaped extension apparatus  5  that has occurred a predetermined time before, and proceeds to step S 424 . In a non-limiting example, the processor  81  newly calculates jump power based on the amount of deformation that has occurred a predetermined time (e.g., five frames) before in the history of the amounts of deformation indicated by the ring deformation amount data D 2   g , and updates the jump power data D 2   h  with the new jump power. In another non-limiting example, the processor  81  calculates new jump power based on the greatest amount of deformation in the history of the amounts of deformation that have occurred during a period of time from the current time to a predetermined time before indicated by the ring deformation amount data D 2   g , and updates the jump power data D 2   h  using the new jump power. 
     In step S 424 , the processor  81  performs a process of moving the player character PC according to the set jump power, and proceeds to the next step. For example, the processor  81  causes the player character PC to move upward in the virtual game space, based on jump power indicated by the jump power data D 2   h , and updates the player character action data D 2   k  based on the location and state of the moved player character PC. 
     Next, the processor  81  determines whether or not to end the displaying of the scene that the player character PC jumps (step S 425 ). For example, if the player character PC has reached a location where the jump ends (the player character PC has reached the target reach height of the jump, the jump ends due to collision with another object, etc.), the result of determination in step S 425  by the processor  81  is positive. If the processor  81  determines to end the displaying of the scene that the player character PC jumps, the processor  81  proceeds to step S 426 . Otherwise, i.e., if the processor  81  determines not to end the displaying of the scene that the player character PC jumps, the processor  81  ends the process of the subroutine. 
     In step S 426 , the processor  81  performs a process of stopping the process of causing the player character PC to jump and move, and proceeds to the next step. For example, the processor  81  sets a state of the player character PC that stops jumping and does not move from the current location to update the player character action data D 2   k . The processor  81  also sets “off” the jump flag indicated by the jump flag data D 2   i  to update the jump flag data D 2   i.    
     Next, the processor  81  calculates game points, and ends the process of the subroutine. For example, the processor  81  calculates game points based on the location that the player character PC has reached by the jump, and updates the score data D 2   j  by adding the game points. 
     Referring back to  FIG.  42   , in step S 411 , the processor  81  performs the process of controlling the action of the player character PC, and proceeds to the next step. For example, the processor  81  disposes the player character PC in the virtual game space based on the location, state, orientation, action, etc., of the player character PC indicated by the player character action data D 2   k.    
     Next, the processor  81  performs an image generation and display control process (step S 412 ), and proceeds to the next step. For example, the processor  81  disposes the player character PC in the virtual game space based on the settings provided by step S 411 . If the label M has been set in step S 407 , the processor  81  disposes an image indicating the label M in the virtual game space. The processor  81  also disposes a virtual camera in the virtual game space, generates an image of the virtual game space as viewed from the virtual camera, and outputs the virtual game space image to the stationary monitor  9 . The processor  81  also causes an image indicating the game score indicated by the score data D 2   j  to overlay the virtual game space image at an appropriate position, and outputs the resultant image to the stationary monitor  9 . 
     Next, the processor  81  determines whether or not to end the game process (step S 413 ). In step S 413 , a condition for ending the game process is, for example, that a condition for ending the game process is satisfied, that the user has performed an operation of ending the game process, etc. If the processor  81  determines not to end the game process, the processor  81  returns to step S 402 , and repeats the process. Otherwise, i.e., if the processor  81  determines to end the game process, the processor  81  ends the process of the flowchart. Thereafter, steps S 402 -S 413  are repeatedly executed until the processor  81  determines to end the game process in step S 413 . 
     Thus, in the fourth non-limiting example game, a predetermined game process is performed by swinging the ring-shaped extension apparatus  5  while deforming the ring-shaped extension apparatus  5 , resulting in an improvement in the user&#39;s bodily sensation in an operation using the ring-shaped extension apparatus  5 . In addition, in the fourth non-limiting example game, when the ring-shaped extension apparatus  5  is not deformed, or when the ring-shaped extension apparatus  5  is deformed and is not swung, the execution of a predetermined game process is limited, and therefore, the predetermined game process is limited by the user&#39;s particular operation. 
     Note that in the fourth non-limiting example game, the user&#39;s operation is performed using the ring-shaped extension apparatus  5 . Alternatively, as in the first and second non-limiting example games, the user&#39;s operation may be performed using the ring-shaped extension apparatus  5  as well as the belt-shaped extension apparatus  6  with the left controller  3  attached thereto. In that case, the process using the output of the motion sensor (the acceleration sensor  114  and/or the angular velocity sensor  115  of the right controller  4 ) of the ring-shaped extension apparatus  5  may be replaced by a process using the output of the motion sensor (the acceleration sensor  104  and/or the angular velocity sensor  105  of the left controller  3 ) of the belt-shaped extension apparatus  6 . Thus, the user&#39;s operation is also performed using the belt-shaped extension apparatus  6  with the left controller  3  attached thereto, and therefore, in the fourth non-limiting example game, the control of the jump power of the player character PC is performed according to a pressing operation of deforming the ring-shaped extension apparatus  5 , and the action control of causing the player character PC to jump is performed according to the motion of the belt-shaped extension apparatus  6  caused by the motion of the user&#39;s leg. Therefore, the variety of user inputs using both of the ring-shaped extension apparatus  5  and the belt-shaped extension apparatus  6  can be increased. 
     Note that in the above non-limiting examples, the ring-shaped extension apparatus  5  includes the ring-shaped portion  201  made of an elastically deformable material, and a process is performed according to an operation of elastically deforming the ring-shaped portion  201 . By thus allowing an operation of causing a main portion of an input apparatus to undergo elastic deformation, the following effects can be expected: the user can easily continuously perform a pressing operation; the pressing operation involving elastic deformation improves the user&#39;s feeling of operation; the pressing operation involving elastic deformation allows the user to easily bodily sense the motion of the player object OBJ; the requirement of a pressing operation motivates the user to perform a physical exercise (e.g., an exercise of moving the arms); etc. 
     In the above non-limiting examples, as a non-limiting example of an operation of deforming the ring-shaped extension apparatus  5 , a pressing operation is used in which the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is deformed from the steady state so that the grip covers  203  and  204  move toward each other. An operation of deforming the ring-shaped extension apparatus  5  may be performed in other ways. For example, a pulling operation of deforming the ring-shaped portion  201  of the ring-shaped extension apparatus  5  from the steady state so that the grip covers  203  and  204  move away from each other, may be performed. 
     The operation of deforming the ring-shaped extension apparatus  5  in the above non-limiting examples includes various embodiments. For example, when a small change occurs in the ring-shaped portion  201  of the ring-shaped extension apparatus  5  from the steady state, it may be determined that an operation of deforming the ring-shaped extension apparatus  5  has been performed. In another non-limiting example, when the ring-shaped portion  201  of the ring-shaped extension apparatus  5  is deformed from the steady state and the amount of deformation is greater than or equal to a threshold set for each game, it may be determined that an operation of deforming the ring-shaped extension apparatus  5  has been performed. 
     Although in the above non-limiting examples, the first control is performed on an object according to an operation of deforming the ring-shaped extension apparatus  5 , the first control may be performed according to other operations performed on the ring-shaped extension apparatus  5 . For example, even when an operational force applied to the ring-shaped extension apparatus  5  so that the grip covers  203  and  204  move toward each other or away from each other, is not strong enough to deform the ring-shaped portion  201  from the steady state, the first control may be performed according to that operational force. Thus, even when the ring-shaped portion  201  is not deformed, the amount of a force applied to the ring-shaped extension apparatus  5  can be calculated using a strain value obtained from the right controller  4 , and a process can be performed using the amount of a force applied to the ring-shaped extension apparatus  5 , instead of the above amount of deformation. 
     In the above non-limiting examples, the main body apparatus  2  and the right controller  4  wirelessly communicate with each other so that the operation data of the right controller  4  is transmitted to the main body apparatus  2 . The operation data may be transmitted to the main body apparatus  2  in other ways. For example, the operation data of the right controller  4  may be transmitted to the left controller  3 , and thereafter, both of the operation data (or processed operation data) of the right controller  4  and the operation data (or processed operation data) of the left controller  3  may be transmitted together from the left controller  3  to the main body apparatus  2 . 
     In the above non-limiting examples, the methods for detecting the orientation and motion of the right controller  4  (the orientation and motion of the ring-shaped extension apparatus  5 ) are merely illustrative, and the orientation and motion may be detected using other methods and other data. The above acceleration sensor and/or angular velocity sensor are a non-limiting example of a sensor that outputs data for calculating the orientation and motion of the right controller  4 . For example, in another non-limiting example, the right controller  4  may include a magnetic sensor instead of or in addition to the acceleration sensor and/or angular velocity sensor, and a magnetism detected by the magnetic sensor may be used to calculate the orientation and motion of the right controller  4 . The methods for calculating the orientation and motion of the right controller  4  are not particularly limited. For example, in another non-limiting example, the main body apparatus  2  may capture an image of the right controller  4  (the ring-shaped extension apparatus  5 ) using an imaging device, and may use the captured image to calculate the orientation of the right controller  4  (the ring-shaped extension apparatus  5 ). Alternatively, data detected by an acceleration sensor and/or angular velocity sensor included in the right controller  4  may be used in the right controller  4  to calculate the orientation and motion of the right controller  4 . In that case, operation data additionally including the data calculated in the right controller  4  and indicating the orientation and motion of the right controller  4  is transmitted from the right controller  4  to the main body apparatus  2 . 
     The game system  1  may be any suitable apparatus, including a handheld game apparatus, or any suitable handheld electronic apparatus (a personal digital assistant (PDA), mobile telephone, personal computer, camera, tablet computer, etc.), etc. In that case, an input apparatus for performing an operation of moving an object may be, instead of the left controller  3  or the right controller  4 , another controller, mouse, touchpad, touch panel, trackball, keyboard, directional pad, slidepad, etc. 
     In the above non-limiting examples, the ring-shaped extension apparatus  5 , when the right controller  4  is attached thereto, functions as an input apparatus equipped with an inertial sensor (e.g., an acceleration sensor or an angular velocity sensor). This function may be implemented in other ways. For example, the ring-shaped extension apparatus  5  itself has the inertial sensor function. In a non-limiting example, the main portion  202  may include an acceleration sensor for detecting an acceleration along the direction of at least one axis occurring on the ring-shaped extension apparatus  5  and/or an angular velocity sensor for detecting an angular velocity about at least one axis occurring on the ring-shaped extension apparatus  5 . 
     In the above non-limiting examples, all the process steps are performed in the game system  1 . Alternatively, at least a portion of the process steps may be performed in another apparatus. For example, when the game system  1  can also communicate with another apparatus (e.g., another server, another image display apparatus, another game apparatus, another mobile terminal, etc.), the process steps may be executed in cooperation with the second apparatus. By thus causing another apparatus to perform a portion of the process steps, a process similar to the above process can be performed. The above information process may be executed by a single processor or a plurality of cooperating processors included in an information processing system including at least one information processing apparatus. In the above non-limiting examples, the information process can be performed by the processor  81  of the game system  1  executing a predetermined program. Alternatively, all or a portion of the above process may be performed by a dedicated circuit included in the game system  1 . 
     Here, according to the above non-limiting variation, this non-limiting example can be implanted in a so-called cloud computing system form or distributed wide-area and local-area network system forms. For example, in a distributed local-area network system, the above process can be executed by cooperation between a stationary information processing apparatus (a stationary game apparatus) and a mobile information processing apparatus (handheld game apparatus). It should be noted that, in these system forms, each of the above steps may be performed by substantially any of the apparatuses, and this non-limiting example may be implemented by assigning the steps to the apparatuses in substantially any manner. 
     The order of steps, setting values, conditions for determination, etc., used in the above information process are merely illustrative, and of course, other order of steps, setting values, conditions for determination, etc., may be used to implement this non-limiting example. 
     The above program may be supplied to the game system  1  not only through an external storage medium, such as an external memory, but also through a wired or wireless communication line. The program may be previously stored in a non-volatile storage device in the game system  1 . Examples of an information storage medium storing the program include non-volatile memories, and in addition, CD-ROMs, DVDs, optical disc-like storage media similar thereto, and flexible disks, hard disks, magneto-optical disks, and magnetic tapes. The information storage medium storing the program may be a volatile memory storing the program. Such a storage medium may be said as a storage medium that can be read by a computer, etc. For example, the above various functions can be provided by causing a computer, etc., to read and execute programs from these storage media. 
     While several non-limiting example systems, methods, devices, and apparatuses have been described above in detail, the foregoing description is in all aspects illustrative and not restrictive. It should be understood that numerous other modifications and variations can be devised without departing from the spirit and scope of the appended claims. It is, therefore, intended that the scope of the present technology is limited only by the appended claims and equivalents thereof. It should be understood that those skilled in the art could carry out the literal and equivalent scope of the appended claims based on the description of this non-limiting example and common technical knowledge. It should be understood throughout the present specification that expression of a singular form includes the concept of their plurality unless otherwise mentioned. Specifically, articles or adjectives for a singular form (e.g., “a,” “an,” “the,” etc., in English) include the concept of their plurality unless otherwise mentioned. It should also be understood that the terms as used herein have definitions typically used in the art unless otherwise mentioned. Thus, unless otherwise defined, all scientific and technical terms have the same meanings as those generally used by those skilled in the art to which this non-limiting example pertain. If there is any inconsistency or conflict, the present specification (including the definitions) shall prevail. 
     As described above, this non-limiting example is applicable as an information processing system, information processing program, information processing apparatus, and information processing method, etc., that can increase the variety of user input methods.