Master O-Dor and his army of Ranx have invaded and slain almost all of the ninja clan except one aged, frail master simply known as Sensei, and his angry, untrained rookie. Ninja is the last of his clan, and this is his quest. Ninja travels from beaches to mountains and beyond earning new ninja belts and recovering lost relics, in preparation to face his ultimate nemesis. The destiny of the world rests on his giant head.