The plot revolves around Kengan or gladiator fighting, a practice that has existed in Japan since the Edo periods. Wealthy merchants and businessmen would hire fighters to combat each other in a public arena. The winner takes it all while offering a spectacle of strength, strategy, and power to crush his enemy. 'Kengan Ashura' follows the story of the mysterious gladiator Ohma Tokita /Ashura who fights on behalf of the Chairman of Nogi Group, to protect his corporate rights. Kazuo Yamashita, an ordinary, 56-year old man is summoned by his company chairman to be the handler for Ashura/Tokita. The duo soon joins hands and prepares for the Kengan Zetsumei Tournament vying for the winning spot as the chairman of the Kengan Organization. Meanwhile, during the fights, Ashura/Tokita and his fighting abilities attracts the attention of many business owners, each lining up to hire the gladiator.