Kureno Rei, the straight-laced, over-serious president of the student council, is the type of person that treats everybody equally. Day after day, he strives to carry out his duties. Suddenly one day, an evil monster called “Dark Genesis” came flying in from space. His aim is “to obliterate the hero who’s occupying the body of a student in the academy”. In order to protect the students, Rei let himself be possessed by the monster…! And then, showing up in front of Rei’s eyes is Fuwa Minori, a delinquent who had no idea that he’s the hero. Rei wanted to clean up the villain in the most amicable way possible, so he approached Minori and deepened their relationship. However, Minori got attracted by Rei and when Minori confessed to him, Rei’s body changed into a monster’s. The way for him to return to normal is through the hero’s kiss…?!!