Masaru, the son, accidentally witnessed his mother, Kondo Ikumi, pleasuring herself one night six months ago. Since then, he has secretly watched her masturbate every night from the shadows. Each time, he becomes increasingly captivated by the strange allure of her body. As the years pass, his mother's sexual desire grows stronger, and unable to suppress it any longer, she begins masturbating while whispering her own name. Watching her, the son grows more and more aroused, unable to contain his feelings toward his mother's body.