A controller for maneuvering a motorcycle, the controller comprising an execution section configured to execute an adaptive cruise control based on a surrounding environment information of the motorcycle, the execution section, in the adaptive cruise control, configured to control a speed of the motorcycle automatically without an acceleration operation or a deceleration operation by a rider of the motorcycle to keep a distance between the motorcycle and a target vehicle at a target distance, wherein the controller further comprises: an acquisition section that is configured to acquire an image data based on a detection result output from a camera mounted to a subject vehicle, the image data that captures another vehicle traveling in a group ride in which a group of motorcycles including the subject vehicle and the other vehicle is traveling in a group; and an identification section that is configured to identify the other vehicle based on the image data acquired by the acquisition section, and the execution section is configured to execute a group ride mode, which is a mode of the adaptive cruise control and is executed during the group ride, based on a travel state information of the other vehicle identified by the identification section, wherein the identification section is configured to: extract, as a vehicle specific information, information specific to the other vehicle based on the image data; and identify the other vehicle by comparing the vehicle specific information to a group-vehicle specific information that is information specific to vehicles included in the group and that is obtained in advance. an execution section configured to execute an adaptive cruise control based on a surrounding environment information of the motorcycle, the execution section, in the adaptive cruise control, configured to control a speed of the motorcycle automatically without an acceleration operation or a deceleration operation by a rider of the motorcycle to keep a distance between the motorcycle and a target vehicle at a target distance, wherein the controller further comprises: an acquisition section that is configured to acquire an image data based on a detection result output from a camera mounted to a subject vehicle, the image data that captures another vehicle traveling in a group ride in which a group of motorcycles including the subject vehicle and the other vehicle is traveling in a group; and an identification section that is configured to identify the other vehicle based on the image data acquired by the acquisition section, and an acquisition section that is configured to acquire an image data based on a detection result output from a camera mounted to a subject vehicle, the image data that captures another vehicle traveling in a group ride in which a group of motorcycles including the subject vehicle and the other vehicle is traveling in a group; and an identification section that is configured to identify the other vehicle based on the image data acquired by the acquisition section, and the execution section is configured to execute a group ride mode, which is a mode of the adaptive cruise control and is executed during the group ride, based on a travel state information of the other vehicle identified by the identification section, wherein the identification section is configured to: extract, as a vehicle specific information, information specific to the other vehicle based on the image data; and identify the other vehicle by comparing the vehicle specific information to a group-vehicle specific information that is information specific to vehicles included in the group and that is obtained in advance. extract, as a vehicle specific information, information specific to the other vehicle based on the image data; and identify the other vehicle by comparing the vehicle specific information to a group-vehicle specific information that is information specific to vehicles included in the group and that is obtained in advance.