Dragon Ball Z is the sequel to the Dragon Ball series. It follows Goku
through his adult life. It showcases his sons, Gohan and Goten, as they
mature. It also displays the evolution of his rivals, Piccolo and Vegeta,
as they move from his enemies to his allies.
Dragon Ball Z begins with a humanoid alien named Raditz arrives on Earth
in a spacecraft. He tracks down Goku and reveals to him that he is his
brother. He also enlightens him on their past. Goku is a member of the
almost extinct race of the Saiyans. They are extraterrestrial visitors
that were sent to destroy worlds. Goku was sent to Earth as a baby to
conquer the planet, but he was injured and lost his memory of his mission.
Goku refuses to help Raditz continue the mission which pushes Raditz to
kidnap Gohan. Goku then teams up with Piccolo who had become friends with
baby Gohan as he trained him. Goku gives his life in order to defeat Raditz
and save Gohan.
Goku's afterlife consisted of him training under Kaio-Sama until he is
revived by the Dragon Balls. He is revived in order to save Earth from
Raditz's comrades, Nappa and Prince Vegeta. During the battle many of Goku's
comrades are killed, including: Piccolo, Yamcha, Tenshinhan, and Chaozu.
The Dragon Balls are also destroyed due to Piccolo's death. Goku defeats
Nappa and Vegeta with the help of Gohan and Krillin. Goku allows Vegeta to
live as long as he leaves Earth.
During the battle, Krillin overheard Vegeta discussing the original Dragon
Balls on Namek, Piccolo's home planet. While Goku is recovering, Gohan,
Krillin, and Bulma head to Namek in order to find the Dragon Balls and revive
Piccolo. However, Lord Frieza is already on Namek attempting to gather the Dragon
Balls in order to be granted immortality.
Vegeta also visits Namek in order to gather the Dragon Balls. He has several
battles with Frieza's henchmen before deciding to team up with Gohan and Krillin
in order to defeat the Ginyu Force (a team of mercenaries summoned by Frieza).
Goku arrives in Namek after healing from his injuries. He battles with Frieza and
ultimately defeats him after going Super Saiyan.
Goku returns to Earth a year later and encounter a time traveler named Trunks
(the future son of Vegeta and Bulma) who warns Goku of the two Artificial Humans
that are coming to avenge the Red Ribbon Army that he destroyed as a child. An evil
life form, Cell, emerged after absorbing two Artificial Humans to achieve his
"perfect form". Cell creates a fighting tournament, the "Cell Games", in order to
decide the fate of the Earth. Goku again gives his life to save Earth, but is
unable to succeed. Gohan turn Super Saiyan 2 and defeats Cell in order to avenge
his father's death.
Goku is revived for one day, seven years later. He meets his youngest son Goten
before he and his allies are drawn into a battle by the Kaioshin against Majin Buu.
After multiple battles that resulted in the destruction and recreation of the Earth,
Goku's life is permanently restored by the Elder Kaioshin. Goku is then able to
destroy Majin Buu with a Genki Dama attack that contains the energy of everyone from
Earth. Goku makes a wish for Buu to be reincarnated as a good person. He later meets
Buu's reincarnation, Uub, at a martial arts tournament. Goku then leaves Earth to
train Uub to be Earth's new defender.
