A mother and daughter, relatives who came to Tokyo, come to stay at the man's apartment, and the three of them sleep side-by-side in a small room. The man can't resist the sight of his niece's breasts as she sleeps next to him, and he reaches out to touch her. Eventually, the mother wakes up to her niece's moans, and instead of scolding her, she says, "I can't resist either," and begins a threesome with the mother and daughter!