Sheet processing apparatus, image forming apparatus, and image forming system

A sheet processing apparatus comprising:

• an ejection tray to stack a plurality of sheet media;
• an internal tray to stack the sheet media in a different position from the ejection tray;
• a first conveyor to convey a sheet medium in a first direction in which the sheet medium is ejected to the ejection tray;
• a second conveyor to come into contact with and separate from the sheet media stacked on the internal tray to convey the sheet media in a second direction different from the first direction;
• a liquid applier disposed downstream from the internal tray in the second direction to perform liquid application to the sheet media stacked on the internal tray;
• a crimp binder disposed downstream from the internal tray in the second direction to execute crimp binding on the sheet media stacked on the internal tray;
• and
• control circuitry configured to control operations of the first conveyor, the second conveyor, the liquid applier, and the crimp binder,
• wherein when a subsequent sheet medium, which is subsequent to a preceding sheet medium of the sheet media stacked on the internal tray, is conveyed in the first direction while contacting the preceding sheet medium, the control circuitry causes the liquid applier or the crimp binder to press a downstream end of the preceding sheet medium in the second direction.