A system comprising a mobile body and a training system for training a user of the mobile body in a predetermined region, wherein the user is aboard the mobile body and operates the mobile body in accordance with a motion command issued from a command unit to the user, the mobile body being separate from the training system, the training system comprising: a first detection unit that is configured to detect a motion of the mobile body that moves within the predetermined region, the predetermined region including an accessible region that can be entered by the mobile body and an inaccessible region that cannot be entered by the mobile body; the command unit that is configured to issue a motion command for the user, for the operation of the mobile body based on the motion of the mobile body detected by the first detection unit; a second detection unit that is configured to detect a distance between the mobile body and the inaccessible region; and a warning unit, wherein the mobile body is an inverted two-wheel vehicle that can travel forward and backward, turn right and left, accelerate and decelerate in accordance with a shift of the center of gravity of the user while maintaining an inverted state of a main body of the mobile body, and that performs inversion control in such a manner that the mobile body moves in accordance with an incline of the main body of the mobile body while maintaining the inverted state, the command unit is configured to issue the motion command such that the main body of the mobile body is inclined away from the inaccessible region, the warning unit is configured to issue a warning when the distance to the mobile body detected by the second detection unit is equal to or shorter than the first predetermined value, the warning unit is configured to issue an exit command to the mobile body, the exit command causing the user of the mobile body to get off, and the mobile body is configured to perform exit control in accordance with the exit command, wherein upon start of performance of the exit control, the mobile body is configured to perform control of reducing its moving speed and gradually restraining turns from being made, subsequently, the mobile body is configured to control, in a time-series manner, its target posture angle in a pitch direction toward the backward side of the mobile body, the target posture angle being an angle of inclination, and when it is determined that the target posture angle is achieved, the mobile body is configured to stop the exit control. a first detection unit that is configured to detect a motion of the mobile body that moves within the predetermined region, the predetermined region including an accessible region that can be entered by the mobile body and an inaccessible region that cannot be entered by the mobile body; the command unit that is configured to issue a motion command for the user, for the operation of the mobile body based on the motion of the mobile body detected by the first detection unit; a second detection unit that is configured to detect a distance between the mobile body and the inaccessible region; and a warning unit, wherein the mobile body is an inverted two-wheel vehicle that can travel forward and backward, turn right and left, accelerate and decelerate in accordance with a shift of the center of gravity of the user while maintaining an inverted state of a main body of the mobile body, and that performs inversion control in such a manner that the mobile body moves in accordance with an incline of the main body of the mobile body while maintaining the inverted state, the command unit is configured to issue the motion command such that the main body of the mobile body is inclined away from the inaccessible region, the warning unit is configured to issue a warning when the distance to the mobile body detected by the second detection unit is equal to or shorter than the first predetermined value, the warning unit is configured to issue an exit command to the mobile body, the exit command causing the user of the mobile body to get off, and the mobile body is configured to perform exit control in accordance with the exit command, wherein upon start of performance of the exit control, the mobile body is configured to perform control of reducing its moving speed and gradually restraining turns from being made, subsequently, the mobile body is configured to control, in a time-series manner, its target posture angle in a pitch direction toward the backward side of the mobile body, the target posture angle being an angle of inclination, and when it is determined that the target posture angle is achieved, the mobile body is configured to stop the exit control.