Mother of a private school ~ Obscene sex education dedicated to students ~

Chihiro runs a cram school at her home and makes a living by teaching several students, including her son Masahiko. After the exam is over, the students report their results with smiles on their faces. However, only Masahiko failed... Everyone celebrates the victory while Masahiko is depressed. When the group takes a breather, his student Honma asks Chihiro for a reward for passing the exam. Chihiro, who has been away for a long time since her husband passed away, reluctantly allows herself to do what he asks. I didn't even know that Masahiko was witnessing the situation...