Developing device and image forming apparatus

The invention provides a developing device and an image forming apparatus. The developing device includes: plural developing units; a rotary body, where the plural developing units are attached, that rotates so as to place one of the plural developing units in a developing position to develop a subject of development; a first driving unit that drives the rotary body; a second driving unit that drives at least one of the plural developing units; and a regulatory mechanism that regulates a position of the rotary body using a rotational force caused in the rotary body in accordance with driving by the second driving unit.