Junna and Senna are twin siblings that live alone. Shortly after the exams, there will be a Cherry Blossom Summer Festival at school, and Senna is excited to create memories with a relunctant Junna. Junna's homeroom teacher calls the twins over to the office to propose that they could live at the school because she is concerned about their situation. Junna doesn't recall the memories of the accident in which his parents died, but he refuses saying that he is encouraged to work hard to support his living because of Senna's existence.