Goku is the main protagonist of the Dragon Ball franchise.
Emperor Pilaf Saga
One day in the woods, Goku was collecting firewood (entire trees) when he hears something. He goes to investigate to find a girl driving car. Goku, having never seen a vehicule before is suspicious. He stops the car and is shot at by the girl driving it, when she sees that the bullets didn't kill him, she introduces herself as Bulma. Goku having never seen a girl before, notices that she doesn't have a monkey tail (like he does) and thinks her strange for it. Though he does notes that his Grandpa Gohan didn't have a tail either. Bulma tells Goku about the Dragon Balls after seeing that Goku had the Four Star Ball, and shows her the two that she had gathered. Goku had believed the Ball to be all that was left of his Grandpa, and is surprised that Bulma has two "Grandpa's". Bulma tells him that with all seven balls a single wish could be granted. Bulma, after seeing his strength, decides that we would be a good body guard, so she has him accompany her, and saves her from a monster not much later.
The Turtle Hermit
While travalling Bulma and Goku happen upon a lost turtle, who is looking for the sea. A giant animal with a sword tries to take the turtle and eat him, but Goku saves the turtle, despite Bulma advising otherwise. The turtle is grateful, and once they reach the sea he says that he will come back with a surprise for them. After a few hours the turtle returns, with an old man on his back. The old an reveals himself to be the Turtle Hermit Master Roshi. He gives Goku a cloud called the Flying Nimbus that only the pure in heart can ride. Bulma, who cannot ride the Nimbus, asks for something from Roshi, as he thinks she notices a dragon ball around his neck. She asks for it, and Roshi gives it to her, but when she mentions that it can grant wishes he wants it back. Bulma asks if there would be anything she could do to get it, and Roshi asks to see her bellybutton, and after flashing it (and more due to her not knowing she lacked underwear), he hands it over.
Goku and Bulma continue their search and come upon a village that is being rampaged by an evil ruler known as Oolong, a powerful shape-shifter. A woman in the town happens to have a dragonball, and she tells them that if they defeat Oolong it is theirs. To do this, Goku is dressed as a girl, as Oolong had been taking girls away from the village. Oolong soon finds out that he was tricked, and runs. Bulma and Goku catch up to him and find out that he is just a shapeshifting pig. Bulma, seeing these powers as potentially useful, drags Oolong along with them.
The Desert Bandits
As their journey continues, the car they are in runs out of gas, trapping them in a desert. There they run into Yamcha the Desert Bandit and his shapeshifting cat Puar. Bulma passes out from heat before they arrive, and Yamcha tries to rob them. Goku fights him, and Yamcha uses his Ulitmate Technique Wolf Fang Fist, but Goku still manages to survive it. Once Bulma wakes up, Yamcha gets shy, as he does around all girls, and runs away. When wondering where to stay that night, Oolong rembers he has a Camper Capsule, so the three stay in that. Oolong drugs Goku and Bulma's drinks so that he can steal the dragonballs, but is interrupt when Yamcha and Puar try to do the same. Both attempts fail, and Yamcha blows up their Camper, and flees when Goku tries to fight him. He gives them a car to say sorry, but had a homing device on it, so he could follow them as they get the dragonballs, and steal them once they get them all.
The Mountain of Fire
Goku and company arrived at Fire Mountain, looking for a dragonball that was hidden there. They met a giant man and upon seeing Goku's nimbus cloud, which he realized Goku got from his former master Master Roshi, he reveals that he is the Ox-King, and that he lives on a castle on Fire Mountain. The King then tells Goku that he had sent his daughter, Chi-Chi, to find Master Roshi and get a magic fan that could put out the flames that prevented him from returning to his castle. He tells Goku that if he gets his daughter and the fan that he can have the dragonball. Goku quickly finds Chi Chi,and they head straight to Master Roshi's island. Upon arrival Roshi tells Goku that he got rid of the fan a while back, and offers to put out the fire himself. The three return to Fire Mountain and Roshi uses a thecnique called the Kamehamehawave to put out the fire on the mountain, and also destroys the mountain itself in the process. Bulma looks through the remains and is able to find the ball intact, and the Ox-King allows her to keep it. Goku asks Roshi to teach him the Kamehameha, but Roshi tells him that it would take 50 years to learn, however, Goku tries, and is able to make a small one. This destroys their car, but the Ox-King gives them a new one, and the journey continues.
The Rabbit Mob
As Goku, Bulma, and Oolong are driving, they realize that they are low on gas, so they stop in a nearby town. After getting the gas, two men in bunny ears confront them. Goku quikly defeats them, and they call in their boss, Monster Carrot, who is a giant rabbit. When Bulma slaps him she turns into a carrot. Goku hits Monster Carrot with his power pole, and makes him change Bulma back. The rabbit does this and them Goku uses the pole to take him and his servants to the moon.
Confronting PilafThe group then goes to find the last ball, which is owned by the evil Emperor Pilaf. One of his henchman, Shu, fires a rocket at their car, and steals a briefcase that contained all the dragonballs, except for the four star ball, which Goku held on to. Yamcha offers then a ride and takes then all the way to Pilaf's castle. They sneak inside, only to be traped once they get in. Emperor Pilaf fills the rooms with sleeping gas. Once they were all asleep Pilaf had his henchman Mai take the last dragonball from Goku. Once they wake up, they wander through the halls to try to get the balls back, however, they only manage to get trapped back in the same room they had started in. Goku uses a Kamehameha which creates a small hole in the wall which they can see Pilaf through. Puar and Oolong turn into bats and try to get the balls back, but before they can Shenron is summoned. Pilaf starts to make his wish, but Oolong interrupts him, wishing for the worlds most comfortable pair of underwear. With this the dragon disappears and the balls scatter across the world. Angered, Pilaf gets them into a room where they will be burned alive when the sun comes up. Yamcha notes the full moon, and Goku tells the story of a monster that appears at the full moon that had killed his Grandpa. Goku was told never to look at the moon. However, Goku accidentally looks at it. When he does, he transforms into a giant ape and breaks through the ceiling of the room. Pilaf and his minions enter a plane and shoot at Goku, but he quickly destroys their plane. Puar remembers that Goku's weaknesses was his tail, so he turns into a giant pair of scissor and cuts it off. Goku returns to normal, and has no memory of what had happened. Goku decides that he wants to train with his master Roshi, and Bulma gives him the dragon radar before he leaves, so that in one year when the dragonballs work again he can find it.
The Tournament Saga
Goku quickly goes to his house to gather a few things, and then heads straight to Master Roshi's island to receive training.