Developer replenishing container and method of reusing developer replenishment container

A method of reusing a developer replenishing container configured to be detachably attachable to a developer replenishing device, and to replenish developer via the developer replenishing device, the developer replenishing container including:

• a developer replenishing portion with a replenishing opening;
• and
• a shutter with at least one shutter opening that can communicate with the replenishing opening, the shutter being configured to open and close the replenishing opening according to attaching and detaching operations of the developer replenishing container,
• wherein the shutter is movable between a sealing position where the replenishing opening is sealed, a replenishing position where developer is replenished from the developer replenishing container via the replenishing opening, and a filling position where the developer replenishing container is filled with developer via the replenishing opening,
• wherein the method comprises the steps of:
• moving the shutter of the developer replenishing container to the filling position, and
• filing the developer replenishing container with developer with the shutter being located at the filling position.