The series begins with a young monkey-tailed boy named Goku befriending a teenage girl named Bulma. Together they go on a quest to find the seven Dragon Balls (ドラゴンボール^?), which summons the dragon Shenlong to grant the user one wish. The journey lead to a confrontation with the desert bandit Yamcha, who later becomes an ally; Chi-Chi, whom Goku unknowingly agrees to marry; and Pilaf, an impish man who seeks the Dragon Balls to fulfill his desire to rule the world. Goku then undergoes rigorous training regimes under the martial artist Kame-Sen'nin in order to fight in the Tenkaichi Budōkai (天下一武道会^?, "Strongest Under the Heavens Martial Arts Tournament") that attracts the most powerful fighters in the world. A monk named Kuririn becomes his training partner and rival, but they soon become best friends. After the tournament, Goku sets out on his own to recover the Dragon Ball his Grandfather left him and encounters the Red Ribbon Army, whose leader wants to collect the Dragon Balls for himself. He almost single-handedly defeats the army, including their hired assassin Taopaipai, whom he originally lost to, but after training under the hermit Karin, now easily beats. Goku reunites with his friends to defeat the fortuneteller Baba Uranai's fighters and have her locate the last Dragon Ball in order to revive a friend killed by Taopaipai.

They all reunite at the Tenkaichi Budōkai three years later and meet Kame-Sen'nin's rival and Taopaipai's brother, Tsuru-Sen'nin, and his students Tenshinhan and Chaozu, who vow to exact revenge. Kuririn is killed after the tournament and Goku tracks and defeats his killer, Piccolo Daimao. The samurai Yajirobe takes Goku to Karin, where he receives healing and a power boost. Meanwhile Piccolo fights Kame-Sen'nin and Chaozu, leading to both their deaths, and uses the Dragon Balls to regain his youth before destroying Shenlong. Goku then begins his battle with Piccolo Daimao, who, just before dying, spawns his son/reincarnation Piccolo. Karin informs Goku that Kami (God), the original creator of the Dragon Balls, might be able to restore Shenlong so that he can wish his friends back to life, which he does. He also stays and trains under Kami for the next three years, once again reuniting with his friends at the Tenkaichi Budōkai. Piccolo Jr. also enters the tournament to avenge his father, leading to the final fight between him and Goku. After Goku narrowly wins, he leaves with Chi-Chi and keeps his promise to marry her.

Dragon Ball Z follows the adventures of the adult Goku who, along with his companions, defends the earth against an assortment of villains ranging from intergalactic space fighters and conquerors, unnaturally powerful androids and near indestructible magical creatures. While the original Dragon Ball anime followed Goku through childhood into adulthood, Dragon Ball Z is a continuation of his adulthood life, but at the same time parallels the maturation of his son, Gohan, as well as characters from Dragon Ball and more. The separation between the series is also significant as the latter series takes on a more dramatic and serious tone. The anime also features characters, situations and back-stories not present in the original manga.

Five years later, Goku is a young adult and father to his son Gohan. Raditz arrives on Earth in a spherical spacecraft and finds his younger brother Goku. Raditz reveals to Goku that they are members of a nearly extinct extraterrestrial race called the Saiyans (サイヤ人, Saiya-jin^?). The Saiyans had sent Goku to Earth as an infant to conquer the planet for them, but he suffered a severe head injury soon after his arrival and lost all memory of his mission, as well as his blood-thirsty Saiyan nature. Goku refuses to help Raditz continue the mission and has to team up with Piccolo, and sacrifice his life, in order to defeat him. In the afterlife Goku continues his training with the North Kaiō until he is revived by the Dragon Balls in order to save the Earth from Nappa and the Saiyan prince Vegeta. In the battle Yamcha, Chaozu, Tenshinhan and Piccolo are killed, and the Dragon Balls cease to exist. Krillin and the galactic tyrant Freeza learns of another set of Dragon Balls by overhearing Vegeta and Nappa talk about the Dragon Balls on planet Namek (ナメック星, Namekku-sei^?). Bulma, Gohan, and Krillin depart for Namek in order to use them to revive their friends. However, the galactic tyrant Freeza is already there doing the same, leading to several battles with his minions and Vegeta, the latter of which teams up with the heroes to fight the Ginyu Force. After Goku arrives, the final long battle with Freeza himself comes to a close after Goku transforms into a legendary Super Saiyan (超サイヤ人, Sūpā Saiya-jin^?) and defeats Freeza.
A group of Androids (人造人間, Jinzōningen^?, "Artificial Humans") created by a member of the former Red Ribbon Army, Doctor Gero, appear three years later, 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 decide the fate of the Earth. After Goku sacrifices his own life to no avail, Gohan avenges his father by defeating Cell. Seven years later, Goku, briefly revived for one day, and his allies are drawn into a fight against a magical being named Majin Boo. After numerous battles, destruction and recreation of the Earth, Goku destroys Boo with a Spirit Bomb containing the energy of everyone on Earth. Goku makes a wish for Majin Boo to be reincarnated as a good person and ten years later, at another Tenkaichi Budōkai, Goku meets Boo's human reincarnation, Oob. Leaving the match between them unfinished, Goku departs with Oob to train him to be Earth's new guardian.

 

The series continues the adventures of Earth's hero Son Goku, who is turned back into a child by the Black-Star Dragon Balls and is forced to travel across the universe to retrieve them along with his granddaughter Pan and Trunks. The three go through various adventures in their journey to find the dragon balls, and are also joined by an artificial mutant life form, who they name Gyru, and who forces them to take him with them when he swallows the dragon radar and integrates it into his system. While in space, they encounter the evil artificial Tuffle, Baby, who intends to destroy the Saiyan race. Baby has the ability to invade other people bodies and turn them into tuffles, as well as using a body to combine it with his own power and become a fighter. After turning practically all of the earth´s population, including the saiyans, into tuffles, Baby decides to remain inside Vegeta´s body and use it to confront Goku. Goku fights him and is defeated, but after having his tail regenerated, achieves the level of Super Saiyan 4, and destroys Baby, propelling him into the sun with a Kamehameha.

After Baby's defeat, Dr. Myuu, a combination of machine and human, creates a replica of Android 17 and has it fuse with the original Android 17, creating Super 17. Super 17 at first seems impervious to Goku's attacks, but when Android 18 attacks him for killing Krillin, Goku takes advantage of the distraction to penetrate through Super 17 with his Dragon Fist technique, then fires a Kamehameha through the wound.
Due to overuse of the Dragon Balls, seven Evil Dragons are then created. All but the most powerful, Syn Shenron, are defeated. Shenron appears to be losing until he absorbs the Dragon Balls - he then gains more power, becoming Omega Shenron, and overwhelms Goku. Goku is about to sacrifice himself to destroy the evil dragon, but then Vegeta turns up in Super Saiyan 4 form, thanks to Bulma's new device, the Blutz Wave Generator. Goku and Vegeta fuse, creating Gogeta, who uses his immense power to taunt Omega Shenron. However, their fusion then ends and Goku loses Super Saiyan 4 form. Eventually, using the energy of every living being in the universe, Goku makes a Spirit Bomb powerful enough to destroy Omega Shenron.