Sayuri lost her husband at an early age and is raising her son Takeo single-handedly. Takeo didn't have a particularly noticeable rebellious period, and Sayuri thought it would be nice if this life continued, even though it was modest. However, one day, Takeo's classmate Koji comes to the house. Koji, who was aggravated by trouble with Takeo in a relationship with a woman, had a strong hatred for Takeo. Koji goes home without doing anything that day, but the next day he shows up at Sayuri's side with a bad friend.