Ayaka has been raising her son Ryuta as a single mother. Beside her is her childhood friend Toru, with whom she secretly has a love affair. However, one day, Ayaka witnesses Ayaka having an affair with Toru. Ryuta is disappointed when he finds out about their true relationship, but at the same time, he becomes aroused by his mother's lewd appearance. Ryuta, who can no longer see his mother as anything other than a woman, attacks her with his huge penis. Kokoro down, Ryuta wishes for his mother's happiness and is tormented by conflict, but Ayaka's feelings also begin to change...