Mami Nagase makes her Fitch debut! Asami, a teacher in the city, meets her younger brother Yuzuru when she returns home, but he has an awkward expression on his face. Later, Asami's parents tell her that Yuzuru has become a recluse, and she becomes worried. She learns that Yuzuru made fun of her for being a virgin, so she decides to teach him how to have sex so that he won't be nervous the first time... Yuzuru is so excited by the situation that she loses herself in it and caresses him wildly, before inserting it raw.