Hoping for a simple life, Japanese family man Akira Saito moves his wife and two sons from Tokyo to Houston to open a restaurant. But beneath Akira's innocent exterior lies his secret identity as a masterfully trained ninja. When crime leader Limehouse Willie wrongfully accuses Akira of stealing a precious necklace, Willie's gang murders Akira's wife. With his mask and deadly weapons, Akira vows to destroy the syndicate responsible for his wife's death.