Hiromu lives next door to Kinuka, a young mother and her young daughter Sayaka. One day the daughter has her panties off and her legs spread while sitting in his apartment! She asks Hiromu to explain what her clitoris is and where her hymen is located. He decides to teach her all about sex.

As Hiromu has sexual relationship with Sayaka he rescues her mother from a burglar. She asks to repay him with her body. If he chooses correctly Hiromu can have sex with both mother and daughter at once!