Junya, who lost his mother a few years ago, lives with his father on a three-legged stool. My father brought Mayu, a remarried partner, at the end of summer when Junya was preparing to take his exams. For Junya, living with Mayu, who is too young to be called mother, is a series of confusions and temptations. It is inevitable for a boy who has just entered adolescence to suddenly appear and realize that his young mother-in-law is a woman.