Fukasawa Miki is a language teacher at a prep school. Lately she has been building up a lot of tension from work so her only stress reliever for her is to indulge in masturbation. On that day she was alone in the classroom, she started masturbation, she keep pleasuring herself, making occasionally some noise but was sure no one was watching so it was ok...

However there was in fact someone watching from the shadows, her (adopted) son Fukusawa Yuuta, the door suddenly opens and her sons looks with a cold glance, Miki tries to explain but...