Medium processing apparatus and image forming system incorporating same

A medium processing apparatus comprising:

• a liquid applier to apply liquid to at least one medium;
• a post-processing device to perform a given process on a bundle of media including the at least one medium on which the liquid is applied by the liquid applier;
• a liquid storage unit to store the liquid to be supplied to the liquid applier;
• a mover to cause the liquid applier to move in a first direction orthogonal to a conveyance direction of the at least one medium and a second direction opposite to the first direction;
• and
• a liquid supplier to supply the liquid from the liquid storage unit to the liquid applier,
• the liquid supplier including an extensible member having an elastic cylindrical part on at least a part of the liquid supplier,
• the extensible member configured to extend and contract in the first direction and the second direction, and
• the extensible member including an elastic coil tube wound in a spiral.