Dragon Ball Z starts out as a alien lands on Earth. The alien comes from the planet Vegeta. He is a Sayian. He comes to see how Earth is since his brother Goku was to take over the planet. Goku is the main star in Dragon Ball, Dragon Ball Z, and Dragon Ball GT.
Meanwhile Goku is to go to a reunion with his son Gohan. While that is happing The alien fights Piccolo the Namek. The Sayian says that his name is Radditz. While Goku and his friends are having fun Radditz is coming near them. Radditz arrives and takes Gokus son Gohan away to his ship as a hostage. Piccolo arrives after Radditz leaves to speak with Goku. Goku wants to join with Piccolo to get Gohan back and they do.
Piccolo and Goku battle for awhile with Radditz and get the crap beat out of them. theres only one thing they can do. Goku graps Radditz while Piccolo charges up his Special Beam Cannon. Unfortunately Goku dies with his brother Radditz. Piccolo tells Radditz how Goku will be able to come back to live with the Dragon Balls. While Piccolo is talking the other Sayians can hear Piccolo talk about the Dragon Balls. The other two Sayians well come to Earth. There names are Nappa and Vegeta. Piccolo sees how powerful Gohan is so he takes him away to trian him.
Goku arrives in heaven to train with King Ki, but first he has to get through Snake Way.