A cartridge includes: a frame; an agitator; a coupling; a first transmission gear; a closing member; and a cover member. The frame has a first wall having a developer filling port, and a second wall spaced apart from the first wall. The agitator is supported to the first and second walls. The coupling is provided at the first wall and receives a drive force from an external drive source. The first transmission gear is provided at the first wall and transmits the drive force received by the coupling to the agitator. The closing member is provided at the first wall and closes the developer filling port. The cover member is provided at the first wall. The cover member includes: a first cover to cover the first transmission gear; and a second cover provided separately from the first cover and to cover the closing member.