A process cartridge comprises a guide member positioned at a side of the process cartridge, a photosensitive drum having an axis L1, and a coupling member having an axis L2, with the coupling member including at least one projection. A relative positioning of the coupling member and the guide member is changeable between (i) a first relative position in which a tip of the at least one projection is a first distance away from an end of the guide member as measured in the direction of the axis L1 and (ii) a second relative position in which the tip of the at least one projection is a second distance away from the end of the guide member as measured in the direction of the axis L1, with the first distance being greater than the second distance.