A year ago, Akari suddenly had a new mother. The son was confused when he was introduced to his young and beautiful stepmother. The son's carnal desires only grew as he was attracted to his stepmother's body... One day, he reached his limit and was thinking of leaving home, when the family decided to go on a hot spring trip. At the hot spring inn, the son's patience reached its limit, and he kneaded and sucked Akari's breasts, licked her private parts, and mercilessly penetrated her. Even though she was his step-son...he knew it was wrong, but he was overcome by the pleasure of immorality and invited his son's penis into him. A forbidden mother-son incest story that ends in a one-night mistake.