Books in the Arms of the Dragon series

Not everyone chooses the streets. Sometimes, when everything is taken away, it's all that's left... The slums of Shindjin have long since been the champion of poverty. Violence and extortion are commonplace, where one's fate can literally be determined by a roll of the dice. A place where the fallout of these actions fall onto the shoulders of children. Shou and Jun are two such children, torn from the comfort of the lives they knew. Now thrust into an environment where organized crime IS law. With nowhere to turn, they're forced to become the very thing that ruined their lives.