Yuka, Rinko, Saki, and Natsumi are childhood friends and classmates who are reaching the conclusion of their second year of middle school and looking forward to summer vacation. Unfortunately, this close-knit group is going through a difficult transition, as Saki is transferring to another school. The ladies are determined to keep their relationship alive, even if just for the duration of the summer. They recall a giant stone they used to visit, tucked away in an ancient Shinto shrine, and the notion that if four friends gathered around it and expressed a single wish, it would be granted. Much to their amazement, they have discovered that the ancient folktale is genuine.