Makoto Saigo is half-American and half-Japanese in small-town Japan with a set of talents limited to playing guitar and picking fights. With rock stardom off the table, he turns toward the only place where you can start from the bottom and move up through sheer merit, loyalty, and brute force - the yakuza.
Saigo, nicknamed "Tsunami", quickly realizes that even within the organization, opinions are as varied as they come, and a clash of philosophies can quickly become deadly. One screw-up can cost you your life, or at least a finger.
The internal politics of the yakuza are dizzyingly complex, and between the ever-shifting web of alliances and the encroaching hand of the law that pushes them further and further underground, Saigo finds himself in the middle of a defining decades-long battle that will determine the future of the yakuza.