A receiving device that is connected to a sheet processing device to receive a sheet comprising: a receiving port that receives the sheet discharged from a discharge port of the sheet processing device: casters that support the receiving device on a floor; and a roller that rides up a support part provided with the sheet processing device at the time of connecting the receiving device and the sheet processing device to receive a part of the weight of the receiving device on the support part, wherein when the roller rides up the support part, a part of the casters floats up from the floor, and the receiving port is positioned to the discharge port.