私より強い男と結婚したいの 清楚な美人生徒会長（実は元番長）の秘密を知る陰キャ（実は彼女を超える最強のヤンキー）

Akira Kogure, a boy who was a bit of a nerd, accidentally discovered that the beautiful student council president, Shizuka Takasaki, used to be a delinquent girl-gang leader. She said she would only marry a man who was stronger than her. But it turned out that Akira was actually also a former delinquent even stronger than her. (Source: Fantasia Bunko, translated)