Though he appears human, it is later revealed that Goku is descended from an alien warrior race known as the Saiyans, who sent him, originally named Kakarrot, to Earth to prepare it for conquest. [ ch. 197 ] Goku sacrifices his life to save the planet from his brother Raditz , [ ch. 205 ] but must quickly get stronger in the afterlife under the tutelage of Kaiō-sama , to save it from the other incoming Saiyans Nappa and Vegeta . He later becomes a Super Saiyan and defeats a powerful tyrant Freeza . This sets the tone of the rest of the series, with each enemy the characters face becoming stronger than the last, requiring them to attain further training. The last battle of the original manga, against Majin Boo , has the entire universe at stake, and as such, has Goku and friends being asked for help from the gods of the universe, the Kaiō-shin .
Seven years later, Goku is allowed to come back to earth for one day. Oolong is at the 25th World Martial Arts Tournament supporting his friends and later goes with Bulma and the others look for the Dragon Balls. Oolong must later take refuge from Majin Buu on Kami's lookout. A day later, he is turned into chocolate and eaten by Super Buu. Later during the battle between Goku and Kid Buu his life is later restored with everyone else on the planet by a wish by Porunga and later gives his powers to Goku's Spirit Bomb to defeat Kid Buu. He later appears at Bulma's house for a party.