How can he fill his mother Chigusa's loneliness? Shinya has been thinking about this for a long time, and today he finally found the answer. After witnessing Chigusa masturbating, Shinya is convinced that the cause of her loneliness is a lack of sex. He decides to comfort her with his body. Chigusa is confused and resists Shinya's unexpected behavior. However, when she realizes that it is her son's way of showing his kindness, she weakens her resistance and accepts their forbidden relationship.