Yuuko had a physical relationship with her son while her husband was away working alone. - We cannot continue this immoral relationship forever. - On the day her husband's business trip ends, she tries to put an end to their relationship, but... - ``Is that really okay, mom?'' Yuuko's heart trembles as she remembers the taste of her son. - But I can't break down here. - Shaking off her unsatisfied son, Yuuko declares that the immoral relationship has ended. - On this day, the long final sex between the two began...