Based on erotic game by Interheart.
At the protagonist school there is a famous club of girls said to bully and target men breaking them down with sex until they are like lifeless husks and move on to next victim. Rumor says all them combine have had over 200 sex partners. One day on train the protagonist is able to hear conversation between college girls and club girls. Turns out they are all virgins who never had sex before. Unlucky (or lucky) for protagonist he is caught eavesdropping. That is day they decide to silence protagonist by finally living up to rumors by making him there target of club.