Goku and Bulma set up a shelter to sleep in. At night, Goku goes out looking for some food. He sees a plane fly overhead, and, thinking that it is a bird, goes running after it. The plane belongs to Mai and Shu, who are servants of Emperor Pilaf. The Emperor is also looking for the Dragon Balls, and he plans to use them to achieve his dream to rule the world. Goku saves them from wolves, and heads back. In the morning, he finds a Giant turtle who is looking for the sea. Goku volunteers to take him there, so he picks up the turtle on his back and begins running, with Bulma following on her motorcycle.

On their way to the sea, Goku and Bulma run into a giant beast that wants to eat the turtle. Goku makes short work of him, and they continue on their way. When they arrive at the shore, the turtle tells them to wait for him. When he comes back, a man is riding on his back. That man is the turtle hermit: Master Roshi, and as a reward for helping his sea turtle, he gives Goku a flying cloud called the Flying Nimbus. Master Roshi himself cannot ride the cloud, because only good and pure people can. Bulma can't ride it either, but Goku can, because he has a good heart. Roshi also gives Bulma the Three-Star Ball (San Xing Qui), not knowing what it is. When Master Roshi returns to his island, he finds Pilaf and his two henchmen searching his house for the Dragon Ball. After he tells them that he gave it away, the three leave his island.

The Dragon Radar leads Goku and Bulma into a remote village. They find that the village is being terrorized by a shape shifter named Oolong. An old woman in this village has the Six-Star Ball (Liu Xing Qui), and she agrees to give it to them if they drive Oolong away from their village. Oolong wants to marry a girl in the village, so Goku dresses up like her to trick Oolong. When Oolong discovers this, he gets very angry. To protect his identity, he reverts back into his original state after he transformed and runs away from the village. Goku follows, and eventually catches and defeats him. With the village saved, the old woman gives them the Six-Star Ball.

Bulma forces Oolong to join their group, thinking that his shape shifting ability will come in handy. Their boat runs out of gas, so they have to walk through the desert. Yamcha, a dangerous bandit, is said to live in this desert. While they walk through the desert, Yamcha and his shape shifting cat Puar ambush them. Goku and Yamcha begin to fight. Yamcha thinks he has won after he uses his Wolf Fang Fist, but Goku is able to get up. Just as Yamcha is about to attack again, he sees Bulma. Yamcha gets nervous around girls, so he panics and runs away.

Oolong remembers that he has a camper Dyno-Cap, so the three spend the night in it. Goku tells Oolong about the Dragon Balls. Oolong drugs the drinks of Goku and Bulma, causing them to fall asleep. Yamcha and Puar have been listening from outside the window, and now plan to take the balls. Puar changes into Goku to lure Oolong (who transformed into Bulma, thinking she was Goku) out of the camper and Yamcha sneaks inside. But what he thinks are the Dragon Ball but after uncovering the "Dragon Balls" and finding out they were Bulma's breasts; Yamcha completely loses it and retreats with Puar who flew away from Oolong, after the shape shifting pig and cat discovered each other's true identities from being Goku and Bulma.

Goku, Bulma, and Oolong arrive at Fire Mountain, with Yamcha and Puar following closely behind. There, they meet the Ox King, who lives in the castle on Fire Mountain. The Ox King notices Goku's flying Nimbus Cloud, and realizes that he must have received it from Master Roshi. He sent his daughter Chi Chi to go to Master Roshi's island to borrow the Bansho Fan to put out the flames on Fire Mountain, but she never came back. The Ox King tells Goku that if he finds Chi Chi and returns with the Bansho Fan, he can have the Dragon Ball that's inside his castle. Goku takes off and finds Chi Chi right away. But after Chi Chi accidentally grabs Goku's tail to help herself climbed onto the Nimbus Cloud which causes him to get dizzy, Yamcha and Puar discovered Goku's tail is his only weak point. And as Goku and Chi Chi leaves for Master Roshi's island, in order to steal the Dragon Balls, they planned to grab Goku's tail to weaken him. After asking for directions from a dolphin, Goku and Chi Chi arrive at Master Roshi's island.

Master Roshi agrees to let Goku borrow the Bansho fan, but when he goes to retrieve it, he remembers that he spilled juice on it and threw it out. He decides to put out the fire himself. When they arrive back at Fire Mountain, Master Roshi uses his famous Kamehame-Ha to blow out the flames. The wave puts out the fire, but it also destroys the entire mountain. With the Dragon Radar, Bulma is able to search through the rubble and find the Seven-Star Ball. Goku asks Master Roshi if he can learn the Kamehame-Ha, but is disappointed to find out that it took the turtle hermit 50 years to learn it. He tries it anyway, and is miraculously able to do it on the first try.

Goku, Bulma, and Oolong drive into a city to get gas, unaware that they are still being followed by Yamcha and Puar, who then hide behind the wall to spy on them. Everyone in this town seems to be afraid of Bulma but after she buys some new clothes and gets rid of her bunny costume, no one even notices her. Just as they're about to leave, two men in bunny ears begin to hassle them. Goku beats both of them up, so they call in "the boss". The boss, whose name is Monster Carrot, arrives. He is a giant rabbit whose special power is his touch; if anyone touches him, he/she turns into a carrot. Not knowing this, Bulma slaps him, turning her into a carrot which Monster Carrot grabs. His two men then start to beat up Goku. Watching from behind a wall, Puar turns into a bird and snatches the carrot out of his hand, and Yamcha beats up the two men to save Goku. Goku then hits him with his Power Pole, forcing Monster Carrot to surrender. He changes Bulma back. Goku then ties up Monster Carrot and his henchmen and takes them to the moon by extending his Power Pole, proceeding to force them to make treats for children.

While Goku, Bulma and Oolong are driving towards the final Dragon Ball, Shu uses his battle robot to fire a rocket at their car. Then he jumps down and runs off with Bulma's suitcase, which contains their Dragon Balls. Goku tries to follow, but loses him. Luckily, Goku still has the Four-Star Ball, so Pilaf can't make his wish to rule the world. Bulma's Dyno-Caps are in her suitcase as well, so they have no ride. With no other options, Yamcha is forced to give them a lift. They arrive at Pilaf's castle. Inside, they come to a dead end, but before they can turn around, a wall comes down, trapping them inside.

After a failed torture of "treatment" on Bulma, Pilaf, Shu and Mai release sleeping gas inside the chamber, which knocks everyone out, including the Emperor himself who did not put on his gas mask. Shu drags Pilaf away, while Mai goes in and steals the Four-Star Ball from Goku while he's sleeping. When they wake up, they realize the ball has been stolen, and begin to run through the hallways. Pilaf sends giant pinballs rolling after them. Just when one of the balls has them cornered, it suddenly backs off, and a wall comes down again. They are trapped in the same room as before. Goku tries to use a Kamehameha wave to blast away the wall, but only manages to open up a small hole that leads outside, where Pilaf is summoning Shenron to grant his wish for world domination. Puar and Oolong turn into bats and fly through the hole to try to steal one of the balls. But before they can get close enough, Shenron himself appears.

Desperate to stop Emperor Pilaf, and just as Goku manages to destroy the wall with another Kamehameha, Oolong interrupts his wish for world conquest with his own: a pair of underpants. This wish is granted, Shenron disappears, and the seven balls scatter all over the earth. Furious, Pilaf sends Mai and Shu after Oolong and Puar, and noticing Goku, Yamcha and Bulma escape, he orders them executed. Many guard dogs suddenly appear: some chase Oolong and Puar and others corner Goku, Yamcha and Bulma. Goku and Yamcha beat these dogs to protect Bulma, and on their way out they find Oolong and Puar. Before they can leave, Mai and Shu corner them with another pack of dogs and themselves. They are transported to a room with a glass ceiling that gathers energy from the sun and heats up. By morning, just as Pilaf planned for revenge on his meddlers, they will be burnt alive. Goku and Yamcha try to break down the walls, but fail. Later that night, Puar is staring at the full moon while Oolong and Bulma argue over their last hope for escape. Goku tells the group about a huge monster that comes out when the moon is full. He said that the monster (though it was clearly Goku, but he is not aware of that) trampled his grandfather Gohan to death, and before that tragedy, Gohan told his grandson never to look at the moon. Alarmed with this detail, Bulma, Yamcha, Puar and Oolong believe that Goku was the monster and fear they will meet the same fate as his grandfather. Despite Bulma's warning, Goku accidentally looks up at the full moon. However, at first, nothing seems to happen to Goku as he shrugs over a big deal, much to the group's confusion. But even though he turns away from the moon and his friends sigh in relief, something snaps in Goku: his eyes turn red, his heart beats loudly with increasing speed, and he begins growing with his clothes tearing apart, his body growing fur, his teeth becoming sharp, his ears pointing up, and his face growing a muzzle. To the gang's horror, it is revealed that Goku is transformed into a wild monkey/ape monster, the Great Ape.

Goku, now a wild Great Ape, begins demolishing Pilaf's castle. Bulma, Yamcha, Oolong, and Puar are able to escape. Pilaf, Mai, and Shu board an airplane and start attacking Goku. They are able to bring him down temporarily, but Goku recovers and destroys their plane. He then picks up Bulma and prepares to eat her. Remembering that his tail is his weak point, Yamcha grabs Goku's tail, and Puar changes into a giant pair of scissors and cuts it off. Goku regresses back to his normal self; naked, and sleeps until morning. When he wakes up, he is shocked to find that his tail is missing and that he is naked, and remembers nothing about his transformation and rampage. He borrows Oolong's pants and finds his Power Pole in the rubble, but finds it hard to balance without his tail. Yamcha and Bulma decide to go back to West City together, with Puar and Oolong tagging along. Goku decides to go find the turtle hermit to get the training he was promised. Bulma gives Goku the Dragon Radar so he can find the Four-Star Ball when the Dragon Balls reappear.

Goku stops by his house to gather his things, then heads towards Master Roshi's island. When he arrives, Master Roshi tells him that he will only train him if he brings him a girlfriend. Goku brings back a big ugly-looking girl but Master Roshi wanted a beautiful girl. So Goku brings a beautiful mermaid, but that doesn't go well either. Suddenly, a small boy named Krillin paddles ashore on a boat and requests training from Master Roshi. With the help of a bribe, Master Roshi agrees to train him. He sends Goku and Krillin into the city to find him another girl. Meanwhile, Yamcha's ship crashed, so he, Bulma, Puar, and Oolong are forced to walk through the jungle and desert.

Because Krillin can't sit on the Nimbus Cloud, he is forced to cling to Goku's back during their search for a girl. They find a girl being attacked by two men. Goku beats up these two guys, and they bring the girl back to Master Roshi's island. Unknown to either of them, the girl, Launch, was being arrested when they found her. When she sneezes, she turns into a grumpy, aggressive, blonde criminal. Back on the island, Roshi likes Launch so much that he agrees to take her on as a student, along with Goku and Krillin. Launch sneezes, and then takes out a machine gun and shoots at the three boys. After another sneeze, everything is back to normal.

Master Roshi packs up his house in a dyno capsule, and the four of them head to a bigger island. Master Roshi tests the boys' speed by timing them in a 100-meter dash. Krillin goes first, and runs the distance in 10.4 seconds. Goku's time is 11 seconds, but after he takes off his old, beat-up shoes, he runs it in 8 seconds. Master Roshi dazzles them by running it in 5.6 seconds. Then he gives them their final test for the day. He makes a mark on a stone, then throws it into the woods, telling them to find it; the loser must go without dinner for the night. Krillin tries to fool Master Roshi with a stone of his own, but Roshi sees through the lie. Goku finds the stone, but Krillin steals it and runs away. Goku catches up, and the two of them fight. Goku wins, so Krillin throws a decoy stone back into the woods, and Goku runs after it, thinking it's the real one. Krillin takes the real stone back to Master Roshi. However, Krillin ultimately loses, as Launch made pufferfish for dinner and didn't know that it was poisonous.

Master Roshi wakes the boys up early to begin their training. Their job is to deliver milk, but there are several miles between each house. After several exhausting runs, they are made to climb a mountain to deliver milk to the monk at the top. While at the top, Master Roshi tells them that in eight months, they will be competing in the 21st World Martial Arts Tournament. This encouraging thought is enough to drive Goku and Krillin through the end of their milk delivery. Once the delivery ends, Master Roshi tells them that they will be delivering milk every day until the tournament. The boys are shocked to find out that the milk delivery was only their early morning training, and that they have much more to do every day. Meanwhile, Yamcha is also training for the World Martial Arts Tournament.

The boys continue their workout by plowing an entire field with their bare hands. After a quick breakfast, they head over to a construction site. Here, they dig holes and haul equipment. Their speed dazzles the foreman. They eat lunch and then take a nap. Goku is getting impatient, and wants to learn fighting moves, but Master Roshi says he will not teach them fighting moves until their bodies are in the proper condition. Their next task is to swim 10 laps on a lake while they're being chased by sharks. Then Master Roshi ties them to a tree and makes them dodge angry bees. At the end of the day's training, Master Roshi tells them they will be doing the same thing every day for the next eight months, but with 50 lb. turtle shells on their backs.

After several months of training, the boys are anxious to learn fighting techniques. Master Roshi tells them that he has no technique to teach them. The whole point of turtle hermit training is to get your body in superhuman condition. He says fighting is just the expression of your power. Then he gives them 100 lb. turtle shells to wear from now on. After a couple of months, the day before the tournament finally arrives. After everyone checks in; Yamcha, Bulma, Oolong, and Puar meet up with Goku. The next morning, Master Roshi gives Goku and Krillin fighting uniforms to wear.

The preliminary rounds are divided into four sections, with the top two from each section going on to the finals. Goku and Krillin are drawn into the same section, but are on opposite ends, so they won't have to fight each other. Goku's first match is against a giant, but he is able to knock him out of the ring with only a slight tap to the leg. Krillin's first opponent is an enemy from his old martial arts school. He kicks his opponent so hard that he breaks a hole in the wall. Bulma, Oolong, and Puar are able to watch the matches through this hole. At the end of the day, Goku, Krillin, and Yamcha all advance to the quarter-final round of the World Martial Arts Tournament.

Goku and Krillin meet up with Bulma, Oolong, and Puar before the finals start. Master Roshi arrives, saying that he missed the preliminaries because of a long line in the bathroom. When the contestants are called to the arena, Goku and Krillin leave, and Master Roshi mysteriously disappears. They draw numbers to set the quarterfinal matches. Krillin is in the first match against Bacterian, a giant whose stench is paralyzing. Yamcha is in the second match against Jackie Chun, and Goku is in the fourth match. The first match starts, and right away Krillin is paralyzed by Bacterian's stench. Just when it looks like he's going to lose, Goku reminds him that he doesn't have a nose, and Krillin is able to get up and give Bacterian a taste of his own medicine. Krillin moves on to the semifinals.

The second match begins. Yamcha tries his best moves against Jackie Chun, but he can't even land a punch because the old man is far too quick for him. The fight ends when Jackie Chun pushes Yamcha out of the ring with his energy. The third match between Nam and Ranfan begins. Nam is fighting for prize money to buy water for his village. Nam hits Ranfan and she starts to cry, but the crying is just an act. She takes advantage of Nam's hesitation and quickly attacks. When Nam is able to defend her attacks easily, she takes off her clothes to distract him. Jackie Chun begins hooting wildly, and Yamcha recognizes this laughter as Master Roshi's. He realizes that Jackie Chun is Roshi. Nam closes his eyes and is able to beat Ranfan.

Goku's match is postponed by rain. While they're waiting for the weather to clear up, they relax in the bar. Giran, Goku's opponent, comes in and gets made fun of by the monks from Krillin's old temple and starts attacking them for bothering him. Yamcha warns Goku that Giran has been known to cheat. When the match finally starts, Giran tricks Goku into dropping his guard, then punches him. Goku responds with a furious attack and throws Giran out of the ring. Giran reveals that he can fly, and he lands safely back in bounds. He then spits rock-hard gum onto Goku, wraply trapping him. He throws Goku out of the ring, but Goku calls the flying Nimbus Cloud to save him. Just as Giran is about to punch Goku, his tail grows back and he dodges the punch. Since he is stronger with his tail, he is now able to break the gum. Shocked at this incredible display of strength, Giran forfeits the match.