Yuuichi Katagiri has struggled with money his whole life, but because to his close network of friends, he has learnt to be satisfied and optimistic. Yuuichi saves up enough money to accompany them on the school trip in order to honor a promise he made to them. When the money goes missing for no apparent reason, suspicion falls on two of Yuuichi's pals, Shiho Sawaragi and Makoto Shibe, who were in charge of collecting the payments. When no one else comes forward, Shiho and Makoto assume responsibility for the failure to protect the money, even though they are innocent. Yuuichi and his buddies get weird letters a few days later, tricking them into meeting up. They are attacked and knocked out as soon as they arrive. They awaken in a strange place.