Reiko becomes pregnant with her lover's child and decides to live with the child alone. Several decades later, her only son, Shinji, worries about Reiko, who has not been able to forget about his father, Oshima. One day, in a fit of desperation, Reiko is embraced by a stranger arranged by Oshima. Seeing this, Shinji unintentionally crosses the line between mother and son... From this day on, the gears of destiny for the two begin to go awry. The highly popular beautiful mature woman, Reiko Makihara, finally takes on the challenge of raw creampie sex for the first time!!