This is the first one I thought of but I think there's another one out there where they also kiss to fight. I'll see if I can find that one.
https://www.mangago.me/read-manga/datte_maou_sama_wa_kare_ga_kirai/
https://www.mangago.me/read-manga/the_chronicles_of_pulau/
This one popped into my head but I don't think it's what you're looking for
LMFAO
It is this one! Tysm
It wasn't but I'm definitely reading it now lol
Yay! Glad it was the right one
So this may sound extremely vague but it's literally all I remember. And it's been in my memories for so long but can't find it. All I remember is that it's sort of like 2 families that have some sort of power. And it's like fallen to 2 guys who have to win against the oth and the only way to win is in a kiss or something. And they constantly kiss and fight. They're not gay in the beginning but like always they do at the end lol