Mari, a high school student, is in love with Ippei, who attends the same prep school, and decides to take the plunge and confess during the summer vacation. Akira, Mari’s best friend and childhood friend of Ippei, is also interested in him, but he supported Mari while hiding his feelings. Eventually, Ippei and Mari begin to associate with each other, but after summer, Ippei begins to experience an incident. The existence of Mari and Akira was exchanged in Ippei, and Mari came to be treated as Akira and Akira as Mari. Moreover, while the situation is getting worse, Mari, who had endured desperately at the beginning, is about to break.