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. (Source: Comikey) *Note: Includes 24 extra chapters.*

Two years after the events of Kengan Ashura, a young man named Narushima Koga aims to enter the Kengan matches, while also seeking out Tokita Ohma for a mysterious reason. He begins to work under Yamashita Kazuo when he meets Gaoh Ryuki, the spitting image of Ohma. Now with a massive showdown between the Kengan Association and Purgatory, another underground martial-arts fighting organization, looming in the background, how will Kouga become strong enough to take part in the legendary Kengan fights? (Source: Comikey)

A prequel for Kengan Ashura.

"The ninja abolition act" after its passing there was no place for ninjas in Japan anymore, which is why Shinoko, 15 years old, had to leave the Public Ninja Junior High she was attending in Japan and, without having good knowledge of the language, moved to US. Where she is to find a completly different things, people and culture, and learn to deal with them... or try to... pretend she does?