OBA-301 The mother at my friend's place where I stayed over was extremely frustrated sexually, her name is Kuramoto Yukine.

While my parents were traveling abroad, I decided to stay at Kousuke's house in the neighborhood. My mother also told me to study hard, so I was purely going to study with Kousuke. Kousuke can also study... But when I went to Kousuke's house, that purpose was ruined in an instant. I accidentally encountered a scene where Kousuke's mother was masturbating. I panicked and looked away, but the situation took a turn in a direction I had never imagined...