The manga centers around Ginjirou Manda, a loan shark business man who is affiliated with many Yakuza gangs in Osaka. He charges an interest rate called toichi — 10% more interest every 10 days, or 365% every year. Thanks to his unrelenting money-collecting tactics, he is feared as "Minami no Oni" or the "Demon" of Osaka's Minami business district. Even when his borrowers tries to scam him, he always finds a way to make them pay his money back. (Source: Anime News Network)

Tatsuya Shirakawa, also known as Hakuryu, is a man who has grown the Kurosu-gumi from a small organization to a large one and dominates the underground area of ​​Shibuya with his wit and action. A ruthless skill that doesn't choose any means. The courage to take a high-stakes gamble without hesitation. A hard-boiled comic depicting the powerful activities of the charismatic yakuza, Hakuryu! Kurosu and Hakuryu, who have fallen into a predicament due to the conflict with the Tenwakai, are trying to revive them...!?

The stage is the Tokyo district of Roppongi and the players are the various Yakuza gangs. One much smaller gang is audaciously trying to carve out territory for itself. That gang's boss relies heavily on his second in command, the notoriously shrewd and powerful young man with the nickname Hakuryu. With Hakuryu's guidance, their small gang of 40 members may be able to stand up to others with even 200 times their numbers. The gang geography of Roppongi is hotly contested, and it will take strength and strategy to get by in that dangerous world!