An apparatus unit that attaches to a media processing apparatus that includes a first unit that includes a first inlet that receives media, a first processing portion that performs first processing on the media received from the first inlet, and a media outlet through which media received from the first inlet is sent out without passing through the first processing portion, and a first tray that protrudes outwardly from a casing of the first unit and that receives media discharged from the first unit after the first processing has been performed, the apparatus unit being configured to be detachably attached to the first unit below the first tray and comprising:
- a second inlet that receives the media sent out from the media outlet and a second processing portion that performs second processing on the media received from the second inlet, when the second unit is attached to the first unit, the second processing portion does not overlap the first processing portion in a media discharge direction from the first unit.