I know the girl was in high school and she was tomboyish with short hair and a flat chest. And she got married? I'm not sure about that. but she started living with an older guy and he had sex with her, showed her she was a woman too (because she had a complex?). I don't remember anything else tho..
you mean this?
http://www.mangago.zone/read-manga/lovers_in_conflict/
Chapter 76 is my Roman Empire.