Maiko, unable to bear the loneliness since her husband left her job three years ago, ends up having a relationship with her eldest son, knowing it's wrong. Her second son, who was watching the act from the shadows, also loves Maiko and becomes jealous of his older brother. A few days later, while cleaning her second son's room, Maiko discovers a large amount of her underwear. There, for the first time, Maiko learns her second son's feelings...