Looks like you'd enjoy the PS2 game Yakuza that came out in '06. Hurry up and play it, the sequel is coming out in a month. As a bonus, all the voices in the sequel are in Japanese. There's a PS3 spinoff called 'Ryu Ga Gotoku: Kenzan' that isn't out in English yet, but it deals loosely with the origins of 'The Yakuza'. Then there's a proper 3rd installment of the main franchise for the PS3 currently being made.