In the manga's story, businesses and merchants wager large sums of money to hire combatants for unarmed hand-to-hand fighting matches. The winner takes all in these Kengan competitions that originated during the Edo period. Merchants use the fights as a means to resolve disputes with each other. The strong and mysterious Ouma Tokita, whose nickname is Ashura, enters these matches. Nogi Group president Hideki Nogi keeps his ambitions to himself when he meets Ashura. Events begin to swirl around the Kengan fights as Ashura enters the fray.