This is a set of commemorative tickets, fans, postcards, etc. from the Doraemon Underwater World, which was located at Yoshioka Underwater Station on the Seikan Tunnel, now closed due to the Shinkansen extension. Some items have stains, wrinkles, and folds. A child stuck a commemorative sticker on the back of a ticket. The commemorative entrance tickets are a complete set. They can be sold separately.