The story unfolds during The Ming Dynasty, as Japanese pirates wreak havoc along the Chinese coast, laying waste to entire towns. The situation becomes even more desperate when bands of ninjas start appearing and target the Chinese military commander, General Chi (Ti Lung). The Master of the Three Arts (who possesses a book illustrating various ninjitsu techniques) is the only one who can combat this new enemy, so he pledges that his students Chau (Chiang Sheng), Mao (Kwok), and Tung (Lu Feng), will join Chi's army in their fight to wipe out the killers.