Responses
Really belated answer to yours but I don't know if you found it already or not.
Anyways it's 'Junai Tokkou Taichou!' and the Sequel about their daughter is 'Seishun Otome Banchou!' both are by Seino Shizuru.
http://www.mangago.zone/read-manga/junai_tokkou_taichou/
http://www.mangago.zone/read-manga/seishun_otome_banchou/
So this manga I read about 5 years ago it was about the strongest delinquent(but he isn't a delinquent) vs this very strong self righteous girl. Anyway, the guy falls in love with her after she punches his face(I think). There's also a sequel but it's about their daughter who looks ugly(? eh not really) cuz she has an oni looking face but the popular guy falls in love with her cuz of her masculinity or chivalry. They both had dark brown skin btw.