Hideki, the nephew, visits the Tachibana household to celebrate Ayano and her husband getting their dream home. That night, Hideki ends up staying at the house and accidentally witnesses Ayano and her husband having sex. Hideki is speechless at the sight of Ayano in such a lewd state, which is a stark contrast to the neat and tidy Ayano he has always known... The next day, when Hideki visits the house again, he witnesses Ayano masturbating with the receiver in her hand, as she was not satisfied with sex with her husband the night before. Hideki can no longer suppress his forbidden feelings for his aunt...