Patent attributes
An image forming system includes a toner container and an image forming apparatus to which the toner container is mountable. The toner container includes a projection that includes an inner peripheral surface centered on a central axis of the toner container. When the toner container is oriented in a predetermined direction, the projection has a downward guide surface facing downward and an upward guide surface facing upward. When the toner container is moved downward in a direction of the central axis toward a mounting portion of the image forming apparatus, (i) the downward guide surface is configured to guide a guided member of the image forming apparatus so that the guided member is rotated in a rotational direction about the central axis, and (ii) the upward guide surface is configured to guide the guided member so that the guided member is moved up after the guided member is rotated in the rotational direction by the downward guide surface.