The game is set in Yamato, a medieval version of Japan ruled by the shogun Tsunayoshi and the daimyōs of the four clans. To become immortal, Tsunayoshi transforms himself into the demon Zanshin, the Dark Warlord, who unleashes his army of darkness to conquer Yamato. Zanshin's forces sweep across Yamato one night, catching the clans by surprise and annihilating them. However, believing that the four daimyōs were killed, Zanshin recalls his soldiers prematurely, leaving one daimyō and seven of his retainers alive. As dawn breaks, the daimyō decides to counterattack, ordering his seven surviving samurai to destroy Zanshin and his minions.