Yuri Akiyama is 41 years old and lives with her husband and son. Her husband is busy working and spends about half the month away on business trips, leaving her to handle nearly all the housework alone. Her son Akira, after failing his college entrance exams, has become a recluse, rarely leaving his room and only going outside about once a week. One day, while cleaning her son's room, she discovered a shocking adult video titled "Incest." At that moment, sensing someone's gaze behind her, she turned around and saw her son standing there.