Divorced from her husband six years ago, Moa had to raise her beloved son Satoshi alone. She always pampered and treated her son as a little boy. One day, when she went to wake up Satoshi, she discovered that his big penis was getting erect! She was surprised that her son had grown up, and his penis was so big. It had been a long time since she had seen a penis, and the lust in Moa awakened. Despite knowing it was wrong, Moa felt like she had lost her mind, she couldn't stop thinking about Satoshi's penis. Unable to control herself any longer, she put sleeping pills in the fruit juice, tricked him into drinking it all. After her son fell asleep, Moa carried out her incestuous, wrongful scheme...