The story begins with a man walking down a field. He has long black hair and is faced by many enemies. It seems that he is part of a large martial arts tournament. This man wishes to become the best fighter. He fights his first opponent and knocks him down in one move.
We then go back into the past, its the year 1939 and the story begins in Seoul. We are introduced to a young man called Choi Bae-Dal. He is a fighter and is fighting against an opponent. Suddenly their fight is interrupted when a plane flies over them. Bae-Dal has long dreamed about being a fighter pilot and since the war has started he always wanted to go and fly planes. Soon after that Bae-Dal decides to make a big move and he hides on a giant cruise ship.
On this ship he hides in the luggage levels and he has to beat up one of the crew members. His goal is to reach Japan and join the military so that he can finally fly planes. BAE- Dal finds an army uniform and when the ship finally reaches its destination he also goes to the city. He escapes as he is afraid of getting caught but soon he runs into a man with a long coat. This man almost immediately recognizes that Bae-Dal is not from around here. This man introduces himself as a detective and threatens Bae-Dal that he will go to prison. Bae-Dal is scared and then the man orders him to give all of his money and belongings. Bae Dal is not really willing but he realizes that he has no choice. Still he decides to fight so he hits the man in his groin. This man yells something in perfect Korean and it’s soon revealed that this man was no detective but a con man and a thief called Chun-Bae. He is also from Korea just like Bae-Dal. Bae-Dal is now furious and starts to beat Chun-Bae but he calls the police over. Bae-Dal now must run from the police. Chun-Bae is very pleased with himself but soon he gets confronted by some criminals as well.
Chun-Bae now must run for his life. He finds a hiding spot in a box that is placed on a giant truck. A woman tells Chun-Bae that he will be killed if the gangsters find him. Suddenly its revealed that Bae- Dal is also hiding in the same truck. The two manage to escape from their captors. They start talking about their lives and what brought them to this point. Bae-Dal admits that he wants to be a pilot and join the aviation school here in Japan. That is a ridiculous idea to Chun-Bae as his experience in Japan has been very difficult. Chun-Bae admits that he has been living a pretty harsh life in Japan and that he has seen what happens to poor Koreans in Japan. After a while he decided to go into crime as that is his only way of making money and surviving.
Bae-Dal tells Chun-Bae that the truck that they are hiding on is actually a military truck going to aviation school. Chun-Bae goes into a panic as he does not want to be part of the military and just die in a war. He jumps out of the truck and makes fun of Bae- Dal. Soon after that Chun Bae gets attacked by those same gangsters and they start running after him. In a pretty comical situation we see Chun Bae once again running after the military truck and asking Bae- Dol for help. Bae-Dol just looks at him for a moment but finally decides to help. Now both of them are on a journey to aviation school.
Bae-Dal is disappointed when he is not welcomed in the aviation school but he soon becomes a prisoner. Bae-Dal and Chun-Bae get captured and are basically treated as slaves. The commander in the camp is an imperialist called Kato. He has a giant ego and is a very dangerous man, all the prisoners in the camp fear him. Kato thinks that Koreans are lower beings than him so he tortures them everyday. Soon enough Chun-Bae and Bae-Dal get tied up to several wooden polls and are left in the open. They stay that way for a while and Bae Dal regrets his decision to come here. After some time there is a sudden aerial attack by the Americans. Their planes arrive and start bombing the entire camp. Many prisoners die as they are tied down. One prisoner right next to Chun-bae dies so he starts to scream from being afraid. Soon enough the entire base is almost destroyed. The attack stops and that is when commander Kato shows up with his men. They decide to release the Korean prisoners as they are not worthy of being here. Chun Bae is furious and he starts to say many insults to Kato and his men. One of the soldiers attacks Chun-Bae but Bae-Dal beats him up. Then another soldier threatens Bae-Dal with a gun but he is not scared. Bae-Dal has had enough of the aviation school and he just wants to die. Suddenly commander Kato stops the soldier as he wants to have some fun with Bae-Dal. Kato is very much amused with Bae-Dal and his spirit and wants to test him.
Kato wants to fight Bae-Dal and wants to test his fighting style called taekkyon. Kato thinks that all of the Korean fighting styles are weak and not deserving. Bae-Dal wants to prove himself so they begin their fight. At first it seems like Bae-Dal is winning. He even manages to get in a few hits. Kato seems injured for a while but then he unleashes his attacks. Kato beats Bae-Dal and almost kills him. He totally humiliates him but decides to spare his life. Kato and his men leave and Bae-Dal is left lying down on the ground.
After many months we now see that Chun-Bae and Bae-Dal now work in the city. Chun Bae is dressed up like a clown and they run a pachinko stall in the crowded market place. They do not make a lot of money but its a fun life. Chun-Bae often must spend many hours trying to get more customers but it works sometimes.
Their pachinko business is soon attacked when they grab the attention of local gangsters. The gangsters are really famous in this part of town and they take money from everyone. Chun Bae then gets confronted by the gangsters and they tell him that he needs to pay money to be protected. Chun Bae does not make enough money as it is, and he does not want to pay them more. The gangsters are very dangerous and they start to threaten him. Then Bae-Dal gets involved. He wants to protect his friend and money so he decides to fight all the gangsters at once. The gangsters attack Bae- Dal and they beat him up pretty badly. There are just too many of them and Bae-Dal does not stand a chance in the fight. He is left really injured and they decide to kill him. Then before they can finish him up a man called Bum-Soo arrives to help.
Bum-Soo is a very famous fighter. He fights off the rest of the gangsters and they run away. Its soon revealed that Bum-Soo has been traveling all around the country and has immigrated from his small town all the way to Japan. Bum-Soo then invites Bae-Doal to join him in the circus where he and many Korean immigrants have found a safe place. The circus pays them good money and they travel all around the country. Bum-Soo has the main goal of helping other Koreans build a normal life in Japan and so helps many of them.
Bae-Dal is very interested in training martial arts from Bum-Soo. At first Bum-Soo refuses to help him. Bae-Dal is very determined and after some time he manages to convince Bum-Soo to train him. Bae-Dal does not want to lose any more fights.
In the meantime Bae-Dal starts to work as a rickshaw driver and he trains in his spare time. He also manages to use his fighting skills when its time to defend some Japanese women who are attacked by American soldiers. Bae-Dal gets involved and he stops the men from harassing the poor women. After that Bae-Dal becomes a bit popular in his small community as a hero. Many people in that community do not know that he is from Korea as they would probably judge him. One of the women he saved is called Yoko and she is very kind. The two start to spend a lot of time together and even become romantically involved.
After some time tragedy strikes the community. Local gangsters arrive and they kill Bum.Soo without mercy. The Koreans from this community decide that they will have revenge and they then attack the Japanese gangsters. There is a giant fight and Bae-Dal arrives as well. He is very fierce and tries to help as many Koreans as he can. Unfortunately he cannot help anymore as he himself gets knocked out by a headblow.
After he wakes up, Bae-Dal is really sad and disappointed in himself. He makes a promise to never lose any fight in his life and to always protect the people in his life. Bae.Dal goes up into the mountains and there he spends some time. He trains every day. He runs every day in the mountains, he uses trees as weights and training equipment. He wants to make his body a perfect fighting machine. He trains his body and spirit.
Finally it’s time for Bae to return from the mountain. He decides to change his name, he takes a Japanese name Masutatsu Oyama. He then decides to travel all around the country and challenge the greatest fighters to duels. He equips himself with his old white karate gi and has very long hair. He starts his travels all around Japan. After some time he reaches a dojo. There he challenges all the members of the dojo and beats them without any problems. All the fighters in the dojo are often defeated in a single move by Oyama.
Soon the entire country hears rumors about this Oyama fighter who is beating everyone in battles. Oyama also gets noticed by the Japan Karate Association. The leader of that organization is former imperial commander Kato. Kato is really offended that someone from Korea is going around and fighting Japanese fighters. He thinks that Korean martial arts do not deserve a place in this country.
Oyama joins competitions in ninjutsu, aikido, kobudo, judo and karate. He wins against every single fighter and their unique fighting style. Everyone in Japan is now obsessed with this legendary fighter. Oyama meets up with Yoko and they talk about life. He admits that he is afraid of dying but more than that, he fears being left a cripple.
Kato sends one of his agents to kill Oyama. This agent actually gets killed by Oyama. Oyama soon learns that the man he killed had a wife and soon. This breaks his heart and he decides to meet the family and say sorry to them. Oyama offers his fighting uniform to the wife of the late fighter. He promises to never fight again and to be her servant. She is at first furious at him but accepts him. Oyama then carries her sunk to the peak of the mountain, this was a longtime wish he had. After that the woman starts to respect Oyama. The wife then tells Oyama to take back his uniform and become the greatest fighter in Japan.
Oyama goes back to the city and there he finds out that the organization wants him to fight Kato. Oyama then once more wears his white gi and goes to face off against Kato.
This is now the same scene from the start of the story. We see Oyama join the tournament and he fights every single fighter that Kato has. He beats everyone and soon he has to face Kato. Oyama and Kato begin their fight and very soon Kato gets injured. Oyama delivers the final blow but does not hit Kato, he decides to spare his life instead.
The story ends with Oyama facing off a giant bull in combat. He grabs the bull by its horns and delivers a fatal blow, showing that he is truly a legendary fighter.