Ma Hon Keung (Jackie Chan), a Hong Kong cop, comes to New York to attend the wedding of his Uncle Bill (Bill Tung) who introduces his new wife to him down at his local Chinese supermarket, which he owns and is in the process of selling to Elaine (Anita Mui). Uncle Bill's friend, Steven Lo, loans him a vintage automobile for the wedding.Later that night, a street gang starts a motorcycle race near Uncle Bill's apartment. They are about to run over his friend's car until Keung jumps down and stops them. He soon starts a rivalry with the street gang when he drives them away from the supermarket that they were robbing and vandalizing.This starts a series of brawls in which the bikies try to corner Keung and finish him off. When a member of the street gang named Angelo (Garvin Cross) gets involved in an illegal diamond deal gone bad and steals the diamonds, the small-time gangsters become the victims of a much larger and more effective criminal syndicate led by White Tiger (Kris Lord).While running away with the diamonds, Angelo leaves them in a cushion, which is unknowingly used by Keung for the wheelchair of a disabled Chinese American boy, who is raised by his elder sister Nancy, a lingerie model/dancer who works in a seedy bar and is an associate/girlfriend of the bikies. Keung befriends Nancy and advises her to stay away from crime. When the gangsters see this, they chase Keung and Nancy. After failing to confront Keung, the bikies turn up at Elaine's supermarket and start vandalizing it, during which two of Angelo's men are captured by White Tiger's men, who turn up at the supermarket in search of Angelo.Angelo's colleagues are unaware of his diamond heist and one is executed in a tree-shredder; his remains are given back to the other gangster to show to his friends as a warning to return the multi-million dollar goods.In the meantime, Keung and Nancy go to bikies' shed after the latest supermarket attack, and Keung defeats them in another brawl, at which point the shredded remains are brought back.Keung agrees to help the bikies' leader, Tony (Marc Akerstream). Keung convinces the street gangsters to reform, then brings the big-time criminals to justice after another long-winded street battle. The syndicate and Keung work out the diamonds are in the boy's wheelchair, and the handover is botched after Nancy and Tony are held hostage by the syndicate; the diamonds are lost after the syndicate uses towtrucks to pull the supermarket apart and the diamonds are spilled as Keung is in the building and knocked over.A long climatic battle occurs in the Hudson River after White Tiger's men hijack a hovercraft and are pursued by Keung and the New York Police Department. The hovercraft finally ends up running through the streets, causing much damage to property. Keung ends the chase by stealing a large sword from a museum and clamping it onto a sports car window and driving into the hovercraft, shredding the rubber undercarriage and immobilising the vehicle and capturing the syndicate men.After shooting one of them non-fatally to force them to reveal White Tiger's location, Keung drives the hovercraft, with the rubber implausibly re-patched with tape, across town to a golf course where White Tiger is playing with subordinates. He runs them over and squashes them non-fatally into the ground. The film ends with White Tiger being squashed, his clothes ripped off his back, leaving him buck naked.
Output: Question: Who is a Hong Kong cop?, Answer: Ma Hon Keung