Decades ago, the evil tyrant Frieza captured and enslaved the Saiya-jin people, Frieza used the people as mercenaries to help him conquer, and sell planets on the galactic market. One of the Saiya-jins, a warrior named Bardock was with his teammates finishing off a planet, when one of the its inhabitants, one called Tooro cursed him. With this curse upon him Bardock was able to see into his future. Bardock later kills Tooro and returns to Planet Vegeta to recover from the battle. Meanwhile, Bardock's second son Kakarotto (Son Gokou) is born. At about this time, Frieza begins to realize that many excellent Saiya-jin fighters were beginning to appear. He realized as a whole the Saiya-jin race was a threat to him and his power. By now Vegeta is only a boy but is still extremely powerful for a child, he is on Freiza's ship as a somewhat slave safe from the upcoming events on Planet Vegeta.

After regaining consciousness, Bardock learns what happens and goes to join his friends that went off to conquer another planet. He arrives at the planet to find all his fellow Saiya-jin dead, one that is barly alive tells Bardock of Frieza's plan to destroy the Saiya-jins and the Planet Vegeta. Frieza's men then find and attack Bardock like they did the other Saiya-jin. During the fight Bardock has a vision of the future and sees Son Gokou growing up, he then loses his balance. Bardock still manages to defeat all of Frieza's hench men except for Dodoria. He easily defeats Bardock with a single energy blast. Meanwhile Son Gokou (Kakarotto) is being sent to Earth to conquer it when he grows older.

Somehow Bardock was able to survive Dodoria's assault, but is unable to fight much because of his injuries. He makes it back to Planet Vegeta and tries to tell the other Saiya-jin about Frieza's plot. They simply mock Bardock thinking Frieza would never do such a thing to his finest mercenaries. Despite the lack of support from his fellow people, Bardock decides he must change Frieza's plans, even if he must do it alone. Meanwhile Frieza's spaceship approaches the planet. Bardock takes off and flies toward Frieza. Hundreds of his minions are dispatched to destroy him. Easily he defeats all who attack him. Then Frieza himself exits the spaceship ready to confront the warrior. Bardock uses the rest of his energy into his most powerful Ki blast and fires it at the tyrant. Frieza simply laughs at Bardock's feeble attempt and creates an energy ball hundreds of times larger and more powerful than Bardock's. The huge ball flies towards Bardock and the planet. Before he dies, Bardock witnesses a vision of his son (Son Gokou) confronting Frieza in the future. He dies happily knowing his son grows up to stop Frieza.

The surviving Saiya-jin are: Vegeta, Nappa, Radditz, Taurus, and Kakartto (Son Gokou). Most of them were on other planets at the time, except for Vegeta who was inside of Frieza's ship at the time. Son Gokou later arrives on Earth and is found by Son Gohan (Grandpa Gohan), and is adopted. Grandpa Gohan later gives him his name Gokou, ironically enough meaning monkey.