``It's erect!'' Yusuke was perplexed as his mother, Rieko, covered him and played with his cock. - But at the same time, I felt my own worthlessness. - It's been three months since my father left. - The mother, who was drowning in loneliness with alcohol, finally became so obscene that she pushed her son down. - Unable to comfort his mother, Yusuke decides that it is a one-time mistake and accepts the forbidden relationship. - However, Rieko's extremely erotic body turns the gentle son who cares for his mother into a beast...