A seemingly blunt man named Yasushi lives on Sanagi(pupa) Island in the Seto Inland Sea, which is famous as a cat island. One day, Yasushi meets a woman named Hanako who wanders around the island soaking wet and asks him to find a "bag" that she had lost after dropping it in the sea. Chika, a childhood friend of Yasushi, and her husband Kiyoshi, who was returning home at the time.