Kako, portrayed by Fumi Nikaido, is a high school girl residing in her family’s restaurant located in Kitashinagawa, Tokyo. Out of the blue, her aunt Mikiko, played by Kyoko Koizumi, shows up, much to everyone’s surprise, as Kako believed she had passed away 18 years earlier. Mikiko’s unexpected arrival stirs up embarrassment within the family because of a previous incident she was involved in. Kako finds herself annoyed when Mikiko moves into her room, and they end up spending the summer together.