Goku is the main character for most of the Dragon Ball/Z series. Later, Goku's son Gohan is seen as the lead role after Goku dies for a second time. Goku starts the manga as a child, a young and innocent boy with black spiky hair, a strange monkey tail and an expanding stick named nyoibo.

Incredibly strong for his age, Goku is found having one of the Dragonballs which he refers to as his Grandfather. The dragonball was the only thing that his Grandfather left before dying, so he considers it to posses his soul. Goku while carrying his lunch home literally bumps into Bulma.
After a brief discussion, and Bulma explaining the power that lies in the Dragonball, both leave to search for the Dragonballs. It is in this way that the series of adventures begin. Soon after, both meet Kamessenin who then gives him his "first" magic cloud, Kintoen or Nimbus, and begins to train the young Goku right from the start.

After some 17 mangas, Goku has had many adventures and friends and is already an adult. Goku is now married to Chi Chi and has a son Gohan, who was named after Goku's Grandfather. During this time things seem to be fine, until the arrival of Goku's brother, Raditz. Through his brother, we discover that Goku isn't really human at all, but was found by his Grandfather inside a space capsule. This meant Goku's Grandfather wasn't his relative and everything was different. Raditz revealed to Goku that he had been sent to Earth in order to destroy it's inhabitants, but due to a big fall when he was young, Goku lost his memory unable to complete his mission, thus becoming the innocent boy that we meet at the beginning of the manga. Goku is really a Saiyajín from the planet Vejiita and has great powers beyond those of any human.

Finally, it was up to Goku and Piccolo, Goku's well known enemy, to destroy Raditz and rid the earth of his threats. After a long battle, Goku and Raditz end up dying, but not before revealing to Raditz the power of the overlooked dragonballs. What Goku didn't know however was that the scouter on Raditz' head also acted as a transmitter, now letting the other two Saiyajins left in the universe know about their power and set out for earth. To prepare for their arrival, the Z-fighters train harder than they ever have before, and Goku in another dimension, travels to King Kai's for training. Gohan is also taken away with Piccolo, who teaches him all he know's.

Whn the Saiyajins finally reach earth, they all clash in a battle never before seen. When Goku is wished back to earth to fight, he easily defeats Nappa, the weaker of the two saiyajins, and fights Vegita, the strongest, until neither one can fight anymore. Goku's son helped in defeating Vegita as well. The Z-fighters let Vegita go, despite their own losses, including Piccolo and the dragonballs.
As Goku recovers from the fight, Bulma, Krillin, and Gohan set off for Nammek, Piccolo's home world, to find more dragonballs to wish everyone back. The reach the planet and are faced with what was then to strongest power in the universe. Goku finally sets off for Nammek as well, traing in hightened gravity the entire way. Before Vegita, Gohan and Krillin were completely destroyed, Goku arrives with his new strength and saves his friends. Then, after wishing back Yamcha, Tien, Piccolo, and Chaosu, the entire team begins to fight with the most powerful creature in the galaxy, Frieza. After much strife and hardship, Goku's friend, Krillin, was destroyed, making Goku angrier than he'd ever been. As he gathered energy, he turned super-saiyajin, a magnified version of his old strength. In this form, Goku managed to defeat Frieza.

Much more happens in the story of Dragon Ball Z, including the cell saga, where the Z-fighters must defeat an army of killer androids, and the Buu-saga, where the must defeat the greatest warrior they had ever faced. Throughout it all however, Goku ended up being the victor, not because he fought for fame, or strived for glory, but because he did it all for others who were less fortunate and less able to protect themselves. Goku's journey eventually led him to fame, but the road he traveled was the best way to get there.