United States Marine Corps commando Frank Dux flies to Hong Kong, China, to take part in the Kumite, a free-style martial arts Olympics secretly held every five years by the International Fighting Arts Association. Testing the skills and spirit of the fighters, the Kumite is a brutal championship competition described as “a cockfight …with people.” Frank trained in Ninjitsu under Senzo Tanaka, a Japanese man living in California. Frank and Tanaka’s son, Shingo, were friends as teenagers, but when Shingo died in an automobile accident, Tanaka had no heir to which he could pass the ancient Japanese martial art, and so he agreed to train Frank as if he were a member of the Tanaka family. They spent over a decade training together. Since Dux is has been recruited by the Defense Intelligence Agency (DIA), two agents, Rawlins and Helmer, are on Frank’s trail because he flew to Hong Kong without applying for leave. Hoping to prevent Dux from fighting, they agents ask Hong Kong police for help, but Captain Chen pretends that Kumite is not happening in the city, and besides, the police are busy with many other things. Frank Dux meets Janice, an American reporter trying to write a story about the secret Kumite. Frank also meets Ray Jackson, another American who has come for the Kumite, and they become fast friends. A local resident named Victor Lin guides Frank and Ray through the alleys to the hidden location of the Kumite, and explains the customs and traditions of the championship. When Frank shows Kumite officials the papers stating he represents the Tanaka family, they refuse to believe they are genuine, because Frank is not Japanese. They require that Frank perform a “death catch” to prove that Senzo Tanaka trained him. Standing before a large stack of bricks, he slaps his hand against the top brick. A moment later, the brick on the bottom of the stack crumbles and officials honor the invitation. The next day, as the three-day Kumite begins, Victor Lin explains there are three ways to win: knock your opponent out, pull your opponent off the platform, or get your opponent to quit by saying “matte,” which is like saying “uncle.” Each match involves heavy physical contact and a lot of blood, which is why the event is called a “bloodsport.” Ray and Frank defeat their first opponents easily. However, both feel intimidated as they watch the current champion, Korean Chong Li, fight. Chong Li has never been defeated, and at the last Kumite, he killed his opponent by kicking him in the throat. When Chong Li reaches the platform, he knocks his opponent out in 14.8 seconds, a new world record. However, Frank knocks out his next opponent in 12.2 seconds, setting a new world record, which enrages Chong Li. Military officers Rawlins and Helmer hear that Frank is staying at the East Lake Hotel and go there to arrest him. Frank offers to accompany them to America when the Kumite is over, but Helmer responds that the military invested too much money in him and cannot afford to let him get hurt. As the officers pull out Tasers, Ray Jackson tackles them, and Frank runs away. That evening, Frank has dinner with Janice, and sleeps with her. The next morning, she asks for his help getting into the Kumite, but Frank insists there is a strict rule barring reporters. Determined to get in, Janice dresses as a high-priced prostitute and gains access on the arms of a rich man who makes many bets. As the match begins, Chong Li defeats his opponent by breaking his leg. Frank easily knocks out his first opponent, and defeats his second by hitting him in the crotch. Next, Ray Jackson faces off against Chong Li. As Chong Li tries to kick, Ray grabs his leg and hits him in the face. Chong Li falls to the mat, and Ray thinks he has won, but as he urges the crowd to cheer for him, Chong Li gets up and kicks him repeatedly. Ray is hospitalized, but expected to recover. When Frank promises to get revenge on Chong Li. Janice is sickened by the idea of him getting back into the ring, but he explains that fighting is something he is good at. Janice goes to the police to ask them to stop the Kumite, but they refuse to get involved. The next day, Rawlins and Helmer are waiting for Frank when he arrives at the match. They again try to use Tasers, but Frank grabs a garbage can lid and deflects them. The agents finally agree to let him fight, and Janice joins them to watch the match. Frank defeats Paco, but Chong Li knocks his first opponent down and brutally punches him in the nose, killing him. Everyone at first cheers for Chong Li, but when officials declare the opponent dead, the crowd stands and turns its back to Chong Li. In the championship match, as Frank and Chong Li face off, the Korean wears Ray Jackson’s headband around his knee as a reminder that he defeated Frank’s friend. After they fight, Chong Li takes a capsule from his belt, crumples it in his hand, and throws the powder in Frank’s face, partially blinding him. Knocked to the mat, Frank closes his eyes and remembers his training with Mr. Tanaka. Using his instincts, Frank blocks Chong Li’s kicks, and delivers his own upward kicks to Chong Li stomach and face. When Chong Li falls to the mat, Frank grabs his neck and forces him to say “matte,” thereby conceding defeat. The referee declares Frank the winner. Officials award him the ceremonial Katana sword in honor of his victory. After Frank and Janice visit Ray Jackson in the hospital, Frank goes to the airport and gets on the airplane with Rawlins and Helmer, who are happy that he is on their side.