Golden Boy: Babel the 2nd

Drugs, women, money, Shinjuku Kabukicho is filled with all kinds of desires. Riku, a high school student, is called the "Golden Boy" in this town, and is even feared by the yakuza. What is the game that Riku plays against the outlaws who haunt this entertainment district, where one puts money and life on the line? (Source: Hero's, translated)