The First episode of Dragonballz takes place when Raditz, Arrives on earth in search of his younger brother, Goku. As we all know Goku is best friends with Bluma, Krillin, and Master Roshi. When all of decide to have a reunion Goku decided to bring his 1st born son Gohan to the party. While Goku and his son catch up on old times with their friends Piccolo, Goku's Rival, Mets with Raditz. In a short brief match, Piccolo realizes he is greatly out matched. Raditz soon finds Goku and his son and tells him of his true heritage. Goku is apart of a ancient race know as the Sayians. Goku was sent to earth to destroy all population so the planet can be used as profit. When Goku hears all this he doesn't believe it, till Master Roshi tells him it is true. Raditz tells Goku he must come with him to met with the 2 other only surviers of the Sayain race. When Goku refuses, and gets into a fight with him Raditz reveals that he is his older brother, and if he doesnt kill 100 people by the end of the day, he will take Gohan instead. When Raditz leaves with Gohan a unexpected helper shows up to help Goku win back his son. It is none other then Piccolo.