Kengan Ashura follows a hidden system where Japanese companies settle business disputes through brutal gladiator matches. Since the Edo period, wealthy merchants and later modern corporations have backed fighters in underground arenas, using their strength to decide deals, alliances, and grudges by force.
At the center is Tokita Ohma, known as the Ashura, who enters the Kengan matches to test his strength and prove himself in a world where victory matters more than money or reputation. Backed by the Nogi Group and paired with Kazuo Yamashita, an ordinary manager suddenly pulled into this violent underworld, Ohma is drawn into a relentless tournament of martial arts bouts, shifting alliances, and dangerous opponents. Across the Kengan Association, Kengan Ashura tracks hard-hitting combat and the race to become the strongest fighter, while corporate rivalry turns every match into a battle with much larger stakes. As the competition escalates, the series keeps the focus on the clash between martial skill and business ambition, where every fight can change the balance of power behind the boardroom doors.