Yonin no Nibiiro

As he walks down the street, Yu spots a naked figure in a fur coat. Bound to be arrested by the police, Yu grabs the strange naked man and starts running. Little does he know he just laid his hands on the yakuza's belonging. That reality quickly catches up to him literally, and before he knows it, Yu is in the middle of yakuza territory. Hot-headed Makoto flaunts his power as usual while calm and collected Ai, his half-brother and first-man, takes care of the aftermath. Gradually, the complications and relations between the yakuza come to light... Yu stepped on a landmine, but how far will the blast reach?
(Source: Futekiya)
Note: Includes three extra chapters.