kill Raditz at the cost of his own life. In the afterlife, Goku trains under the North Kaiō until he is revived by the Dragon Balls to save the Earth from the invading Nappa and Vegeta. In the battle, Yamcha, Chaozu, Tenshinhan, and Piccolo are killed, and the Dragon Balls cease to exist. Kuririn and the galactic tyrant Freeza learn of another set of Dragon Balls on the planet , Piccolo's homeworld. Bulma, Gohan, and Kuririn search for them to revive their friends and restore Earth's Dragon Balls. Their goal leads to several battles with Freeza's minions and Vegeta, the latter standing alongside the heroes to fight the Ginyu Force, a team of mercenaries. The long battle with Freeza ends when Goku transforms into a legendary and defeats him. Barely surviving, Freeza recovers and goes to Earth to take his revenge on Goku; however, he is killed by a Super Saiyan from the future named Trunks. Three years later, a group of created by a member of the former Red Ribbon Army, Doctor Gero, appears, seeking revenge against Goku. During this time, an evil life form called Cell also emerges and, after absorbing two of the Androids to achieve his "perfect form", holds his own fighting tournament to challenge the protagonists. After Goku sacrifices his own life to no avail, Gohan avenges his father by killing Cell. Seven years later Goku, briefly revived for one day, and his allies are drawn into a fight against Majin Boo. After many battles, including the destruction and re-creation of the Earth, a resurrected Goku destroys Boo with a Genki-Dama (a sphere of pure energy drawn from all intelligent beings on Earth) and wishes for him to be reincarnated as a "good person". Ten years later, at the Tenkaichi Budōkai, Goku meets Boo's human reincarnation, Oob. After testing his powers, Goku departs with Oob to train him to be the Earth's new guardian. Production Writing Within roughly six months of creating the popular manga Dr. Slump in 1980, Akira Toriyama wanted to end the series but his publisher Shueisha would only allow him to do so if he agreed to start another serial for them shortly after. He worked with his editor, Kazuhiko Torishima, on several one-shots but none were successful. Torishima then suggested that, as Toriyama enjoyed kung fu films, he should create a kung fu shōnen manga. He was inspired by Hong