Unabara Domain—home to nightmarishly strong students and masters of martial arts of all kinds. The lord of the Unabara has decided that whichever of his sons discovers the strongest martial arts style will be his heir, but when 28th son Naoyoshi Washizu decides on Ogama-style practitioner Gama Kurogane, son of notorious father and scion of a “weak” style, to represent him, the odds seem bleak. But between Naoyoshi’s determination and Gama’s hard-earned strength, they may yet come out on top!
Gama and the others storm Unabara castle only to find their path immediately blocked by a monstrous giant lurking beneath the ground—Arimaru! Gama and his allies struggle to ward off Arimaru’s underground assault until Shinnojo puts his life on the line and successfully brings her to the surface! However, it’s Zenmaru who steps in to fight Arimaru in Shinnojo’s place. Determined to evolve as a warrior, he draws his Sadanaga against a deadly foe!