Moshimo Youmuin no Oji-san ga Saimin o Oboetara... ~Onna Kyoushi o Midara ni Otosu, Nikuyoku no Houetsu Saimin~

The protagonist, Suguri Suguru, is subjected to power harassment on a daily basis by the school principal, Togasaki Touko.

Funakoshi Sumiya (self-proclaimed hypnosis counsellor) notices this and scouts Suguri as a hypnosis trainer. The counsellor, Sumiya, says that he would like Suguri's help in seducing the female teachers he has chosen as his targets. As a reward for seducing them, he is told that he can set one of them free, and after much deliberation, Suguru decides to help.

His main reason for doing so is his desire to get revenge on the school principal who bullies him. He learns simple hypnosis techniques and prepares to seduce women. Once he has learned everything, Suguri finally sets his sights on female teachers...

[Translated from the the official site]