Michiru, a friend of Kenta's mother, comes to stay at his house. Kenta, who has just learned how to masturbate, cannot hide his excitement at Michiru's attractive body. He finds Michiru's underwear and, not satisfied with just masturbating to it, he starts to touch Michiru's big breasts and indulge in them. His desire escalates even further! Wanting that voluptuous body, Kenta sets up a nighttime assault on Michiru...