Miyo Sasaki is an energetic high school girl who comes from a broken family consisting of her unconfident father and an overly invested stepmother, whose attempts at connecting with Miyo come across as bothersome. Seeing Kento Hinode as a refuge from all her personal issues, she cannot help herself from forcing her unorthodox demonstrations of love onto her crush. While Miyo is unable to get Kento's attention as herself, she manages to succeed by interacting with him in the form of a white cat, affectionately nicknamed "Tarou" by Kento. But Miyo soon realizes that she cannot help Kento with the various problems she overhears in her cat form and is now caught between two tough choices. Will she continue her relationship with him as a cat, or will she reveal her identity and risk what they have in order to help him as her human self?

Ever since the death of his grandfather, Yasuji, Kousuke Kumagaya has grown distant from his close friend, Natsume Tonai. Having grown up together like siblings in the same apartment building, the two now find themselves at odds with one another due to Natsume's inability to let go of the past. This rift is further exacerbated by the news that their former complex will soon be demolished. Hearing about a ghost that is supposedly haunting the old complex, Kousuke's friends drag him into the demolition site to look around. When Kousuke finds that Natsume is also there, they get into an argument over an old camera that once belonged to Yasuji. This results in Natsume running off with it, but just as she is about to fall off the rooftop, a torrential downpour envelops the entire building, flooding the ground around it. The young children now find themselves drifting at sea with the apartment building acting as their ship. Unable to communicate with the rest of the world, Natsume and Kousuke must reconcile their differences if they want to stand a chance at finding their way home.