Start of the "Saiya-jin Saga". It has been five years since the defeat of Piccolo Daimao, and Goku and Chichi have settled down at Goku's old home in Mt. Paozu. They now have a son named Gohan, named after Goku's grandfather. One day Goku is supposed to meet his old friends for a reunion at Kame House house, but before he leaves he must find Gohan, who is lost in the forest. Meanwhile, a mysterious Saiya-jin warrior lands on Earth and searches for someone named Kakarotto. Instead, he finds Piccolo, who is still training to defeat Goku.
Friends arrives at Kame Sen'nin house for a reunion, but an alien warrior crashes the party. He reveals himself to be Raditz, Son Goku's older brother, and he explains the history of the Saiyan-jin. He also reveals that Kakarotto is the birth name of Goku, a Saija-jin himself, who was sent to Earth as an infant to extinguish human life.
Hoping to force Son Goku into following his orders, Raditz abducts Gohan. While Goku and the others decide what to do next, Piccolo shows up. Realizing that Raditz is too powerful for either fighter to defeat alone, Son Goku and Piccolo forge an alliance and confront him.
In a rage, Gohan breaks free from his prison and attacks Raditz. Goku distracts Raditz in an attempt to save Gohan, and Piccolo charges his Makankôsappô for one final attack. Meanwhile, two other Saiya-jin hear Piccolo speak of the Dragon Balls through Raditz's scouter and decide to come to Earth.
Son Goku's friends form a plan to bring him back to life with the Dragon Balls, and Piccolo takes Gohan away to train him in preparation for the arrival of the two Saiya-jin. Meanwhile, Kami-Sama meets Goku in the Other World and sends him down the Snake Way in search of Kaiô-Sama, a legendary martial arts master with the ability to make Goku strong enough to help his friends battle the Saiya-jin.
Piccolo leaves Gohan to fend for himself in the wilderness for six months so that he can become stronger and learn to take care of himself. Meanwhile, Krillin tries to break the news of Gohan's training and Goku's death to Chichi. Also, Kami-Sama foresees his own demise and wonders about Piccolo's motives, and Goku continues his journey down Hebi no Michi.
Kuririn returns to Kame House without telling Chichi of Goku's death and Gohan's training with Piccolo, and Chichi and Gyûmaô set out to find what he's hiding. Yajirobê brings a message to Kuririn, telling him to find Yamcha, Tenshinhan, and Chaozu and to meet back at Karin's for special training in preparation for the Saiya-jin, because Kami-Sama himself will train them. Meanwhile, as Gohan tries to find the courage to get down from the cliff he glances at the full moon, which turns him into an Ôzaru, and Piccolo must find a way to stop him. Also, Goku continues down...
Gohan is attacked by wild animals. As he attempts to escape, he falls into an underground cavern, where he finds a robot who teaches him to take care of himself. Meanwhile, Goku, who is still on Hebi no Michi, takes a break from running to eat clouds.
Kuririn picks up Yamucha, who is playing in a baseball game. Meanwhile, Gohan gathers food and mends his wounds, and he helps a dinosaur who has been injured. Also, Gokû wakes up from a nap and continues down Hebi no Michi.
While on their way to Earth, Vegeta and Nappa take a quick detour in an attempt to conquer the planet Arlia. Meanwhile, Gohan dines on the tail of a dinosaur, Lunch runs from the police, and Gokû continues down Hebi no Michi.
Kuririn and Buruma search for Tenshinhan and Chaozu, who are training under a waterfall, and Ranchi tries to convince Tenshinhan to rob banks with her. Meanwhile, Son Gokû gets a ride in Hebi no Michi from an Untenshu and Gohan continues his training. Also, Pikkoro trains by lifting the Pyramids with his mind, but he accidentally causes and earthquake which affects everyone.
Having fallen off from Hebi no Michi, Goku finds himself in block 1 of Hell. There he meets Gozu and Mezu, two "oni" who will help him find his way back to Hebi no Michi if he can defeat them in a series of challenges. Meanwhile, Ten Shin Han and Chaozu climb Karin's Tower; Lunch meets Upa and Bora while trying to find a way to follow TenShinHan up the tower; and Gohan runs from a tiger.
Having caught up to where he was when he fell, Goku continues down Hebi no Michi. He stops at a palace, thinking it to be where Kaio-Sama lives, but it turns out to belong to Hebi Hime, who likes him so much that she won't let him leave. Meanwhile, Gohan watches Piccolo train; Kuririn, Yamucha, TenShinHan, Chaozu, and Yajirobe begin their training with Kami-Sama.
Gohan does his homework in a cave as he thinks about how much he misses his parents. He then makes a boat and sails across the desert, where he is chased by a giant bird. He crash lands on an island, and he befriends a tiger as he looks for a way to escape. Meanwhile, Piccolo splits himself in two and fights his doppelganger as part of his training. Also, Goku continues down Hebi no Michi.
Piccolo begins heavy training with Gohan. At Kami-Sama's lookout, Kuririn, Yamucha, TenShinHan, and Chaozu grow impatient because they feel that they aren't learning anything from Kami-Sama's training, so Mr. Popo uses the time chamber to transport them back in time to planet Vegeta, where they fight two Saiya-jin.
Piccolo is forced to fight Gohan, who turns into Ôzaru when he sees the moon that is projected from Goku's Saiya-jin spacecraft. Meanwhile, Son Goku reaches the end of Hebi no Michi and meets Kaiô-Sama.
In the next phase of Goku's training, he must hit Gregory, Kaiô's grasshopper, with a sledge hammer; also, Kaiô-Sama tells Goku about the history of the Saiya-jin. Back on Earth, Piccolo continues training Gohan, and Kuririn, Tenshinhan, Chaozu, Yamucha, and Yajirobe train at Kami-Sama's lookout.
Kaiô times Goku on catching Bubbles and Gregory, and Goku practices the Genki Dama technique. Goku then contacts Master Roshi and tells him to wish him back to life, and he begins his journey back down Hebi no mishi. Meanwhile, as the Z Senshi finish their training, the Saiyajin land on Earth.
Nappa destroys East City, and he and Vegeta head toward Piccolo and Gohan; the other Z Senshi also fly to where the battle is going to take place, with Kuririn arriving first; Yajirobe tells a group of people about the Saiyajin.
The Z Senchi and the Saiyajin agree to fight a series of one on one matches, and Tenshinhan and Yamucha fight the first two Saibaiman while their friends watch helplessly on TV; Son Goku races back home as fast as he can; Yajirobe talks to a group of reporters about the battle.
The battle with Nappa continues as Pikkoro and Kuririn try to ambush him while he fights Tenshinhan. Also, Kami-Sama senses that the end of his life is approaching, and Son Goku continues on Hebi no michi.
Piccolo, Kuririn, and Son Gohan fend off Nappa as Son Goku makes his final approach on Kinton cloud. Meanwhile, Bulma thinks about happier times and Gyumao tries to stop Chichi from joining the battle.
As Kami-Sama fades from existence while Piccolo dies, he tells Mr. Popo to go to Namekku-sei to retrieve their Dragon Balls; Gohan, in a rage, fights Nappa; Uranai Baba arrives at Kame House to announce Son Goku's return; Goku arrives on the battlefield and fights Nappa.
Son Goku fights Vegeta, and he uses the Kaiô-Ken technique; Kuririn and Son Gohan fly back to Kame House; Lunch drinks her troubles away in a bar; Vegeta causes a massive earthquake and storm while powering up.
Son Goku and Vegeta continue to fight, and Goku uses a triple Kaiô-Ken. Frustrated that he can't beat Goku, Vegeta attempts to destroy Earth using his Galick Gun attack, and Goku gives everything he has in a desperate attempt to stop it.
Vegeta uses his energy to create artificial moonlight and turns into Ôzaru, and Son Goku, after trying to fight him, realizes that his only chance for victory is to use the Genki Dama. Meanwhile, Son Gohan flies back to help his dad.
Son Gohan fights Vegeta as Kuririnn prepares to throw the Genki Dama that he created from the last of Son Goku's energy. Also, Karin shows up at the Kame House, and he, Roshi, Bulma, and Chichi go to help.
The battle with Vegeta is over--the survivors are picked up by Roshi, Bulma, Chichi and Karin, and everybody mourns their fallen friends. Also, Kuririn devises a plan to go to Namekku-sei to find their dragon balls and revive their friends.
Bulma and her dad work on Kami-Sama's spaceship; Son Gohan sneaks out of his room to train and Chichi looks for him; Son Goku, Son Gohan, and Kuririn continue to recover in the hospital; Bulma recruits Son Gohan and Kuririn to go with her to Namekku-sei.
Son Gohan, Kuririn, and Buruma try to occupy themselves on their ship until they are attacked by a squadron of smaller ships. They escape, but they are captured by a command ship that is camouflaged to look like the rest of space, and they leave their own ship to investigate the inside of the command ship. Also, Son Goku is scolded by his doctor for training in the hospital, and Vegeta travels through space planning his revenge on Son Goku.
While Kuririn, Son Gohan, and Bulma are held at gunpoint, the ship enters an asteroid belt. After they help their captors through the asteroids, the kids tell them about how the villainous Freeza killed their parents and friends and took over their planet. Meanwhile, Son Goku is scared to death of getting a shot at the hospital, and Vegeta arrives back at Freeza's base.
Bulma crashes the spaceship on what she believes to be Namekku-sei, and she, Kuririn, and Son Gohan are nursed to health by two mysterious aliens. Afterward, while one of the aliens stays behind to fix the ship, the others begin searching for the Dragon Balls. Meanwhile, Vegeta continues his recovery, and Son Goku gets antsy in the hospital.
Son Gohan, Kuririn, and Buruma continue looking for the Dragon Balls. They have to retrieve one from inside a tornado, and they go to a castle where a giant lives to find the next one. Meanwhile, Son Goku sneaks out of the hospital to train, and Vegeta finishes his recovery.
Kuririn, Son Gohan, and Buruma find the 6th Dragon Ball in an ice cave, and they must escape before the cave collapses. They also search for the final Dragon Ball. Meanwhile, Vegeta stews over his defeat, and he looks for Freeza. Also, Son Goku continues training, despite his injuries not being fully healed, while Master Roshi and Chichi look for him.
Zâkuro and Raichi explain their illusion to Kuririn, Son Gohan and Buruma. As Kuririn and Son Gohan try to escape from the lake monsters holding them captive, the two aliens try to figure out the spaceship. Also Kuririn, Son Gohan and Buruma attempt to escape the planet and continue their journey to Namekku-sei. Meanwhile, Vegeta continues to fly to Namekku-sei, and Son Goku tries to sneak out of the hospital again.
Freeza and his henchmen, Zarbon and Dodoria, gather some Dragon Balls. Kyui (Cui) tracks down Vegeta and is surprised by his strength. Two of Freeza's scouts attack Son Gohan and Kuririn while Son Goku does mental training in the hospital.
Son Gohan, Kuririn, and Buruma hide in a cave when they sense the energy of Freeza and his cronies, who are looking for the 5th Dragon Ball. Son Gohan and Kuririn follow them while Buruma calls Kame Sen'nin and informs him of the trouble, he in turn tells Son Goku. Yajirobe brings Son Goku some senzu beans, and Goku, now healed, leaves the hospital and picks up a spaceship that Dr. Brief built for him to use to get to Namekku-sei.
As Son Goku trains on his ship, Son Gohan and Kuririn watch as Freeza and his henchmen Zarbon and Dodoria, interrogate a group of Namekkuseijin about the Dragon Ball, and another group of Namekku Senshi show up to stand against them.
After Dodoria easily defeats the three Namekku senshi, Freeza sends Chôrô to get the Dragon Ball. But when Dodoria begins to execute the remaining Namekkusei-jin, Son Gohan has seen enough, and he intervenes. Meanwhile, Son Goku continues to train on his ship.
Son Gohan, Kuririn, and Dende escape from Dodoria; Burîfu Hakase tells his daughter Buruma that Son Gokû is on his way; Vegeta confronts Dodoria and learns the truth behind the destruction of his home planet.
After evading Vegeta, Krillin, Gohan, and Dende return to the cave and meet with Bulma. While Goku is outside his ship fixing damage to the hull, Dr. Brief informs him that the asteroid that did the damage also knocked the ship off course, and that he is now headed directly for a star. Vegeta goes to the next village to find a dragon ball.
Vegeta fights a group of Nameks for the dragon ball that they are holding. Frieza sends Zarbon and another soldier to find the remaining dragon balls. After hearing about how Vegeta terrorized Earth, Dende decides to take Krillin to see the eldest Namek so that they can form an alliance and defeat their foes. Goku continues his training in 20 times normal gravity and Yamcha, Tien, Chiaotzu, and Piccolo arrive at King Kai's planet to train.
Goku tells King Kai and Yamcha about what has been happening on Namek, but when King Kai learns that Frieza is there, he warns Goku to stay away. Piccolo, Yamcha, Tien, and Chiaotzu must make King Kai laugh before he will train them. Krillin and Dende hide from Vegeta, who has sensed them; Vegeta fights Zarbon.
Zarbon reveals his ferocious transformation to Vegeta; Kuririn and Dende continue their journey to the eldest Namekkuseijin; Son Goku trains under 50 times normal gravity; Tenshinhan, Yamucha, and Chaozu train as Piccolo meditates.
Guru reads Krillin's mind and sees his good intentions, so he decides to help Krillin in his quest. Zarbon reports to Frieza, who grows angry with Zarbon's carelessness regarding his fight with Vegeta. Gohan goes after the dragon ball that Vegeta hid and Goku can't move after his latest training session.