Mio lost her husband, who was much older than her, to illness, and lived with her husband's stepson, Kenichi. After her husband's death, the thirty-something woman in the prime of her life, who had always maintained her chastity, sometimes yearned for human contact, but she suppressed those feelings in order to raise her son. But one day, when she saw her stepson's energetic morning wood, she couldn't resist and ended up sucking his erect penis...