Mr. Tsan, is a doctor and master of Wing Chun, whose martial lineage traces back to the style's founder. He is grudgingly persuaded by Fei Chun, his lead student, to teach kung fu to Cashier Hua, a patient hiding out at his residence. Hua had previously overheard a businessman named Mo and several of his men plotting to take over the town by killing the head of the town. Unfortunately, Hua made the mistake of warning Mo's wormy henchman, Master Yao and a trap was set that nearly cost the poor cashier his life. Whilst in hiding, Hua sends Fei Chun to warn the town head. Ignores the advice, the town head is later attacked by Mo's men, although its unclear whether he escapes or is killed after a protracted fight. Meanwhile, Tsan runs Hua through an elaborate series of Wing Chun training sessions before he falls victim to a vicious trap set by Mo who has learned of Hua's whereabouts. With nothing left to lose, Hua, Fei Chun, and Tsan's niece split up to use specific Wing Chun styles against Mo's leading fighters. Trouble mounts when its discovered that Fei mixed up the fighter's names and each of Tsan's students have to improvise in order to win against their opponents.