I'm looking for Yaoi Mangas with Foe-yay relationship, which means love/sex relationship between two enemies ( and rivals). (http://tvtropes.org/pmwiki/pmwiki.php/Main/FoeYay)

I would love it if they first hate each other, but they don't really have to . A strong rivality is also ok.
And MORE IMPORTANT : i want a HAPPY ENDING. Not that i hate sad endings or anything but right now i'm in the mood or something happy .

TL;DR : Enemies/Rivals (males) that first hate each other but end up loving each other ( and possibly in a relationship).

Thanks !