Since the Edo periods of Japan, gladiator arenas exist in certain areas. In these arenas, wealthy business owners and merchants hire gladiators to fight in unarmed combat where winner takes all. Tokita Ohma, nicknamed "Ashura", joins these arenas and devastates his opponents. His spectacular ability to crush his enemies catches the attention of the big business owners, including the Nogi Group chairman, Nogi Hideki.
Beginning two years after the game-changing Kengan Annihilation Tournament on Ganryu Island, we follow the path of Narushima Koga as he is enlightened to the underground world of the Kengan matches.