BL manga

i think it takes place in italy and is about sum mafia shit, where the half-bloods are looked down by the pure-bloods. and the pure-blood is divided by two, one is the "gentlemen" and the other is the "carefree" and each of them has a leader. MC is the leader of the gentlemen side, and ML is the leader of the carefree side. in order to be the leader, you must be a pure-blood because you are leading the pure-bloods ofc thats common sense. but one day the ML found out that the MC is NOT a pure-blood, MC is half-blood. then MC ran away (ML is in love w him btw) then ML chased him and they made an agreement, yk what agreement that is