Hey! I'm looking for this yaoi manga where there is this kind of competition between the "...

Hey! I'm looking for this yaoi manga where there is this kind of competition between the "hero" et the "villain".
And even though the "hero" is the hero, he's more of a yakuza than anything.
They also have powers, the villain one is to make people submissive and the hero one to make people do good action.
Their weak spot is in there mouth at some particular place.
Thank you ^^