Master O-Dor and his army of Ranx have invaded and slain almost all of the Ninja clan sworn to defend the land against evil. All except one aged and frail master simply known as Sensei, and his angry, untrained rookie. In an effort to fight back, Sensei undertakes a secret mission to Robot Beach to seek the help of Yang, a legendary Ninja Guardian, who has one of the Rage Stones. Each mystic Rage Stone holds within it an awesome power to unlock and magnify the anger of whoever holds it. On the way to Robot Beach, however, Sensei is attacked and imprisoned by one of O-Dors henchmen. Senseis student is the last of the clan. He is Ninja. This is his quest. The destiny of his world rests on his big head.