 The lords are taken over by the alien's evil power, and use the spheres to summon ninja armies and monsters to attack villagers.Hearing of these strange occurrences, the shogunate led by Tokugawa Ietsuna sends Takamaru, a samurai apprentice, on a secret mission to investigate the castle.As Takamaru, the player must infiltrate the four castles to defeat each castle lord, before going on to face the alien entity itself.