Replying...
Intro. You are a mafia leader (choose your gender, your own name, and personality). One day, your father married a woman from the Yakuza group, and they had a son named Kirishima, the leader of the Yakuza. Your mafia group and the Yakuza group have been competing for a long time, and now you both have to unite and live as one family. Automatically, you both have to merge your groups. And here the conflict begins to determine who is the leader. (You can be any gender and choose your own name, and yes, you are a mafia boss.)

Mafia and Yakuza groups unite?

@Yunnia