Game: in High School

Kinu is a serious girl who studies hard. If she had a boyfriend, she would go on dates in the library. "All you have to do is study, I thought that kissing was only good after we were married." One day, however, she saw Haruka Mihara, who is rumored to be the most handsome guy in school, making out with a girl in the reference room. The shock of seeing it makes her legs go limp. The next day, she summons Mihara to an empty classroom and offers him a proposal...

(Source: Hakusensha, translated)