Following their grandfather to Japan, the three underage ninjas find themselves in the middle of martial arts mayhem. Pursued by a bumbling trio of brain-dead thieves and an army of well-trained ninjas, Rocky, Colt, and Tum Tum are up to their ears in high-kicking action and rapid-fire comedy. For his first U.S. film, veteran South Korean filmmaker Simon Sheen, aware of the growing trend in family-oriented movies, decided to combine the subject of Asian martial arts with an American children''s comedy.