One morning, mother Yasuko visits her son to wake him up. Still half-asleep, she absentmindedly touches her lower body and is shocked to find her pubic hair fully grown and her arousal intensely heightened. Sensing her son's virile energy, Yasuko loses her maternal composure and instinctively begins moving her body. When her son finally opens his eyes, Yasuko watches him masturbating and, unable to resist, joins him in pleasure, eventually reaching a powerful climax. From that day on, Yasuko grows increasingly closer to her son, deepening their forbidden bond.