Issei Yotsuya inherits an old camera from his great-grandfather. While out trying it out, he accidentally drops it from a bridge. Looking down he is shocked to find it has hit a young girl wearing a kimono and hakama on the head. He quickly takes the unconscious girl home, but when she awakes, it seems she has lost her memory. But then Issei discovers a 80-year-old photograph featuring the very same girl in his apartment...