A year after losing her husband, Ayako Inoue had been masturbating every night late into the evening. Her son Noboru, who had secretly watched her each time, began dreaming of having a sexual relationship with his mother. The thought of having sex with Ayako constantly filled Noboru's mind. On the night of the first anniversary of his father's death, as Ayako quietly lit incense before her husband's portrait, Noboru suddenly acted on his desire and made it a reality.