Piccolo was killed during the battle with the Saiya-jin, and his spiritual counterpart Kami died along with him. Therefore, the Dragon Balls lost their power, and could no longer be used to grant wishes. Our heroes realize that the only way to bring their dead friends back to life is to journey to Piccolo's homeworld of Namek, and find the original Dragon Balls, which were Kami's model for the batch he created on Earth.
Goku's body has been completely ravaged by the battle with Vegeta, and he is not capable of making the journey. So, Buruma, Kuririn and Gohan make the journey to Namek in the spaceship Kami used to get to Earth thousands of years ago
Once there, they find that not only has Vegeta healed and come looking for the Dragon Balls, but an unbelievably powerful being named Freeza is after them as well. Freeza's henchmen Kiwi, Dodoria, and Zarbon are there to aid him in his bid for immortality, but all of them are dispatched singlehandedly by Vegeta. During this time, Gohan and Kuririn save a Namek child named Dende from certain death, and he leads them to the Namek Elder, who awakens dormant powers within both.
Meanwhile, Goku is on the way to Namek in a space pod that enables him to train at 100 times Earth's gravity, and his power level is rising dramatically due to the all-out endurance test he is putting his body through. At the same time, Freeza's reinforcements have arrived on Namek: 5 fearsome warriors known as the Ginyu Tokusentai, Rikuum, Bahta, Jees, Gurudo, and Ginyu, a group so powerful that they give Vegeta, Kuririn, and Gohan no choice but to either join forces, or die.
Vegeta kills Gurudo without a problem, but next up is Rikuum, who proves to be a vicious opponent, and suceeds in not only knocking Kuririn and Vegeta down for the count, but almost killing Gohan. Goku finally arrives at the scene just as the battle has reduced everyone to utter helplessness, and he defeats Rikuum and Bahta with astonishing ease.
Ginyu then jumps into the fray, and he and Jees are soon defeated, but not before badly damaging Goku's body, which confines him to a healing capsule. Our heroes have nothing now but to face their final confrontation with Freeza himself. Nail, a Namek warrior, is sent to fight Freeza as a distraction to give the Earthlings a chance to gather the Namek Dragon Balls, and when they finally do, the Namek Dragon, Polunga, is summoned. Unlike the Earth balls, these grant three wishes, the first of which brings Piccolo back to life, and the second which transports him directly to Namek. Before they can make the third wish, however, the Namek Elder, who is the source of power for the Namek balls, dies, and the balls vanish.
Piccolo rushes to aid the others, and en route, encounters the dying Nail, who has been defeated by Freeza. Nail offers Piccolo his life force, and they merge into one being, nearly doubling Piccolo's powers.
Piccolo confronts Freeza and fights with all the spirit he has to avenge his people. The battle forces Freeza to mutate three times, increasing his power with each transformation.
Goku finally recovers from his wounds and returns to the fight, just in time to see Vegeta fatally wounded by Freeza. Vegeta begs his rival to make sure Freeza is defeated by Saiya-jin hands. Vegeta's last tearful wish is for Goku to become the warrior of legend, the Super Saiya-jin, a goal that Vegeta had been working towards all of his life. Vegeta then dies, and Goku takes on Freeza.
The battle is long and arduous, and Goku tells his friends to board his space pod and leave, because they are just getting in the way. But Freeza, unwilling to let anyone escape, kills Kuririn, which sends Goku over the edge. In an ocean of pain and fury, he transforms into the most powerful being the universe has ever known, the Super Saiya-jin.
Meanwhile, on Earth, the ressurected Kami has gathered his Dragon Balls and wishes everyone killed by Freeza back to life. This wish brings Polunga back as well, with the third, still unused wish, which transports everyone except Goku and Freeza to Earth, since Namek is on the verge of destruction. Everyone then appears on Earth, including all the Namek-jin, as well as Vegeta.
The battle between Freeza and Goku continues, and our hero is winning. The fight culminates with Freeza making a final attempt to kill Goku, which backfires, and he ends up slicing himself in half. He begs the Saiya-jin to help him, and Goku's good nature cannot ignore Freeza's pleas. He shares just enough power to allow his enemy to escape, but Freeza takes advantage of the opportunity, leaving Goku with no choice but to shoot a fireball in Freeza's face, finishing him once and for all. Namek then explodes, and Yamucha, watching with Kaiou and the others from Heaven, telepathically contacts Buruma to break the good news about Freeza's defeat, as well as the sad news about Goku's almost certain death.
130 days pass, and, on Earth, the Namek balls are used to summon Polunga. Buruma wishes for the remains of Goku and Kuririn to be brought back home. The dragon answers that this is fine for Kuririn, but Goku is not dead, so he doesn't have any remains to be teleported. This is confusing to everyone, since they all assumed Goku had died along with Namek, but they continue. The second wish brings Kuririn back to life, and the third ressurects Yamucha.
Another 130 days pass, and the balls are used again. The first wish brings back Tenshinhan, the second Chaozu, and the third creates a new Namek, a "replacement" world for its stranded people.
After months and months of fighting, sacrifice, and nightmarish ordeals, everything and everyone is finally at peace. But there is a concern that is first and foremost in everyone's thoughts: Goku has still not returned to Earth, and his whereabouts are unknown...