Eriko is a married woman who is married to a man with a child. She dreams of a life of living happily together as a family of three, but her stepson Akio is always cold towards her. Furthermore, her husband is away on a long business trip, and Eriko is troubled by the discord between them. The only thing that saves her is the kindness of Akio's cousin, Jiro. However, Akio, who is filled with inferiority complex, does not like this and in revenge, demands sex, saying, "If you want to become a family, do as I say." Eriko forgives him, saying, "Just once...", but his orders do not end there...