Kenta, who is a ronin student, is staying at his uncle's house in Tokyo for a while to take summer courses at a cram school. His uncle and aunt just got married last year and are trying to conceive, but perhaps because his uncle is old, his sperm is weak? They are having a hard time conceiving. Soon after Kenta comes to Tokyo, his uncle goes on a week-long business trip to the countryside, but as soon as his uncle leaves, his aunt seduces Kenta by wearing revealing clothes, and Kenta's reason collapses as she seduces him with her back-stepping ass (※buttocks) that hits the spot for big butt lovers...