For years deprived of marital intimacy and suffering from pent-up desire, a married mother turns to an erotic book she finds stored in her son's room to satisfy her own lust. At that moment, her younger son Kazuya suddenly appears and catches her in the act. Overcome by suppressed urges, the mother loses control and begins licking Kazuya's pubic hair. Unseen in the corner of the room, her older son Norikazu watches in shock. From that moment on, an unusual awareness begins to grow in Norikazu's mind toward his mother. One day, upon noticing the scent of her pubic hair clinging to her underwear, he finds himself overwhelmed by uncontrollable desire.