One day in Feudal Japan, Kid Niki, the most radical of ninjas, is training at his Ninja School. Suddenly, a passing bird is struck down by an arrow and lands at Niki's feet. Attached is a note explaining that Niki's girlfriend, Princess Margo, has been kidnapped by the evil Stone Wizard. With the cry of "Will help you!" Niki bursts through the wall of his school and sets off on his quest to save Margo.