Nobuko's loneliness had reached a critical point. Since the birth of her only son, Takashi, her husband had become increasingly indifferent to the couple's activities, and they had been sexless for a long time. Unable to stand it any longer, Nobuko becomes violently promiscuous through masturbation. Takashi happens to be passing by, and seeing Nobuko's lewd and lonely appearance, he becomes anxious to help his mother in any way he can. Takashi's tenderness touches Nobuko, and though she knows in her head that she shouldn't do it, she engages in intercourse with him. Nobuko is completely captivated by Takashi's adulterous behavior and finds herself unable to stay away from him even for a moment.
