An image forming system includes a process cartridge having an image bearing member, processing structure acting on the image bearing member, a toner container containing toner used in a developing operation, and a gripper used when the process cartridge is mounted within the image forming system. The gripper also serves as an aiding member for removing a seal sealingly closing an opening of the toner container. With the foregoing construction, it is possible to provide a process cartridge and an image forming system capable of removably mounting a process cartridge therein, which can prevent an operator from forgetting to remove a seal prior to using a new process cartridge.