放課後凌辱性徒会～M会長の白濁ぶっかけ下克上～

Student president Sera is the main character, and he has a secret crush on Ryou, the vice president.
One day Sera finds Ryou's gym suit and can't help but start masturbating.
After getting caught in the act by Ryou, the secretary, and the accountant, Sera becomes the sexual target of three other people. But then through special circumstances the roles are reversed...

[Edited from DLsite English]