ShiroPro:RE Collaboration Koga Castle 110 Yen Stamp Set of 20

This is a set of 20 110-yen stamps that can be used on standard mail, created in collaboration with "Koga Castle" from the popular tower defense game "Oshiro Project: RE ~CASTLE DEFENSE~," distributed by DMMGAMES and boasting over 4 million registered users.
They will be sent on an A4-sized sheet.