In the heart of a lush tropical jungle, young Yaiba Kurogane trains in swordsmanship with his father Kenjuurou, oblivious to the modern world. One day, they find themselves aboard a cargo container bound for Japan. There they meet Kenjuurou"s former adversary Raizou Mine and his daughter Sayaka. With no other choice, Yaiba strikes a bargain with the Mine family: defeat their top student and he may remain.
Leveraging his unique techniques and immense power, Yaiba secures a spot. Seeking stronger foes, he follows Sayaka to school—where he is swiftly bested by Takeshi Onimaru and declares him his new rival. As Onimaru wields the ancestral sword and gains demonic abilities, Yaiba must intensify his training to surpass him once more.
