A multi-motor system includes motor assemblies, each including a motor, a communication circuit to receive a command transmitted from outside, a control circuit to generate a control signal that rotates the motor with a controlled variable that is designated by the command; and a motor driving circuit that causes a current to flow in the motor based on the control signal. The command includes control data indicating the controlled variable of the motor in fixed data length, the controlled variable being expressed at least with an integer, and position-designating data designating a position of the radix point in the control data. The position-designating data is independently determined for each motor assembly.