Kengan Ashura

Kengan Ashura (ケンガンアシュラ) is a Japanese manga series written by Yabako Sandrovich and illustrated by Daromeon. It was serialized on Shogakukan’s Ura Sunday website from April 2012 to August 2018, with its chapters compiled into twenty-seven tankōbon volumes. A sequel, titled Kengan Omega, began in January 2019. It was adapted into an original net animation (ONA) anime series.

Summary:

Since the Edo period of Japan, gladiator arenas have existed in various forms around the world. In these arenas, wealthy business owners and merchants hire gladiators to fight in unarmed combat where the winner takes all. Tokita Ashura Ohma joins these arenas and devastates his opponents. His spectacular ability to crush his enemies catches the attention of big business owners, including the Nogi Group CEO, Nogi Hideki.