An image forming apparatus includes a development cartridge having a developing roller. The developing roller includes a roller body, and a shaft to pass through a central axis of the roller body. A coupling structure is disposed at an end part of the shaft, is movable from a first position to a second position, and includes a first coupling piece and a second coupling piece. Positions of the first coupling piece and the second coupling piece are maintained with respect to one another by a static frictional force between surfaces of the first coupling piece and the second coupling piece to hold the coupling structure in the first position. When a predetermined force overcomes the static frictional force, the first coupling piece and the second coupling piece disengage from one another to allow the coupling structure to move from the first position to the second position.