Young warrior, Onimaru is given the Oni Gauntlet as he rushes to defend his village from the demon hordes of Nobunaga Oda. Onimaru soon discovers from the old man Sandayu, that although he has been living in the peaceful province of Iga, he is of the Oni clan and had been secreted away. Additionally, with the power of the Oni Gauntlet, he can absorb the souls of enemies and use the demon Genma stones to recreate lost weapons and armor. With this new knowledge of who his is and of his destiny, he assembles a hasty squad of fighters including his sister Ororo and sets off to avenge his province and stop Nobunaga's demonic war upon the land.