After Erion is destroyed, Vegeta suggests th the and Goku take Gohan,Trunks, and Goten to Erion's planet to meet the surviving saiyans Erion spoke of. Goku is eventually convinced, and Bulma builds a spaceship for the five of them. Goku travels to King Kai's to see if he could pin-point the saiyan's energy. He finds it and reports back to Vegeta.
After about a month of travel, they all touchdown on Erion's planet and upon landing they find a ransacked city abandoned of any inhabitants. While scouting the city, Trunks finds a group of about 100 saiyans lead by Captain Kalgon. Kalgon explains that after Erion left, alien invaders captured many of his followers and took them to some far off, unknown location. The reason Kalgon and his men were not taken was because they were part if a rebel alliance against Erion's rule. While conversing with the saiyans, Vegeta introduces Goku as Kakorot, which catches the attention of a young saiyan named Celeb. Celeb tells Goku that his father was Bardock's brother, which made them cousins. Celeb tells the Z fighters about the cruelty of Kalgon, of how he killed his father for not successfully completing a mission. No one wishes to oppose Kalgon because he had the power to go super saiyan. Goku decides to help Celeb by talking to Kalgon.
Meanwhile, Califort Kalgon's top lieutenant, delivers the planet's dragon balls to Kalgon, which they had initially gathered to use against Erion. At that moment Goku appears before Kalgon, but Califort was able to hide the dragon balls from him. Kalgon and Goku get into an argument about the treatment of his men. Goku demonstrates that he can go well beyond Kalgon's power, and challenges him to a duel to decide the fate of his men. Kalgon accepts, and says they will fight at dawn the next morning.
Under the cover of night, Califort wishes to the dragon of Erion's planet, Despar, for Kalgon to be given enough power to defeat Goku. However, Despar is a dragon of immense consequence. Every time a wish is made on the dragon balls of Erion's planet, a consequence is made upon the person who the wish benefits. So in turn, Despar gave Izor even more power than Kalgon.
The next morning, Kalgon and Goku met in the city center to square off. To Goku's surprise and horror, Kalgon immediately goes Super Saiyan 5. Goku matches his form an the two begin to fight, finding they are evenly matched. The fighting temporarily ceases, and then Kalgon extracts a syringe from his belt and injects it into his neck. The Saiyan captain then turns into a monstrous ghost great ape. Kalgon now has more than enough power to beat Goku.
When Vegeta and the others try to help Goku, Kalgon's men attack. An all-out war between the saiyans has begun. Celeb turns against his old saiyan comrades to fight for his cousin and his friends. He is not the only one to join the Z fighters, a handful of other saiyans join Goku's side, one of them is Celeb's long-time crush, Mya.
The fighting intensifies, saiyan warriors die on both sides. Kalgon has beaten Goku into submission, but before he can squash him under his foot, The drug Kalgon injected into himself wore off, and he returned to normal size.
Kalgon goes mad with his new found power and decides to blow up the entire planet by creating a ball of white light over his head, similar to a spirit bomb, but with his own energy. Goku launches a Kamehameha at the ball of death to try at stop it, but he doesn't have enough energy left. Luckily Vegeta, Gohan, Goten, and Trunks all showed up and fired their own attacks to try and stop Kalgon's attack. All they could do however, was momentarily stop it.
Kalgon is confident that he has won, he watches the Z fighters struggle with his attack and his men run away towards Goku's hip to try to get off planet before it blows. He is so over conceited with himself, he does not notice Califort power up to ssj5 behind him until it's too late. Califort kicks Kalgon into the white energy ball he created, then flies off, killing most all of Kalgon's men along the way to get to the Z fighter's spaceship. He hijacks it, then flies off planet.
Goku and his friends dig deep and find the strength to pentetrate the energy ball with their kamehameha waves. Inside the ball, Kalgon is skewered by the waves of energy and explodes inside of the energy ball.
When it is all over, only the Z fighters, Celeb, Mya and a handful of loyalists to Kalgon were left. The loyalists allowed for the Z fighters to leave with the other two Saiyans in some spare pods.
After a long, 3 month journey, the Z fighters return to Earth with two new recruits.
