An imaging system includes a control unit. Also, an imaging device and an information processing device with a cellular phone function include a fixed state in which the devices are fixed to each other, and a separated state in which the devices are separated from each other. Fixation/separation information indicates the fixed state or the separated state. The control unit performs, for the imaging device or the information processing device, different state controls in accordance with the fixation/separation information and an operation state of the cellular phone function. For example, user-friendliness of both the cellular phone function of the information processing device and an imaging function of the imaging device improves by performing different state controls at the time of reception of an incoming call, an incoming call responding state, and an incoming call response end in accordance with the fixed state or the separated state.