Years after Cell's defeat, peace reigns on Earth and Gohan enjoys spending his days between school desks and superhero exploits. Meanwhile, a new Tenkaichi Tournament is being organized that will feature new enemies anticipating the greatest threat facing humanity. This is how it begins the saga of Majin Buu, the last of Dragon Ball Z.
Gohan befriends Videl, Mr. Satan's daughter, who persuades him to enter the tournament. Everyone trains hard and on the day of the competition, Goku returns to earth from the afterlife. Many new faces can be found at the tournament, including including Kaioshin, Kibith, Spopovich, and Yamu.
Despite preparing alongside Gohan, Videl finds it very difficult to face Spopovich. The brawler, like Yamu, turns out to be part of a plan to drain the energy of the best fighters. Pleased with the results after taking Gohan's energy, the two villains exit the tournament, followed by the protagonists. Enter the villain infant, Son of the wizard Bibbidy who created Majin Buu. Intending to avenge his father killed by a Kaioshin, Babidy wants to free the evil creature and it takes a lot of energy to do it.
As No. 18 wins the Tenkaichi Tournament, the Z Warriors on Babidy's spaceship attempt to get closer to the antagonist, facing off against powerful opponents like Dabula, the lord of the underworld. Now close to the goal Babidi manages to control Vegeta. The Saiyan pride resurfaces and the prince decides to face Goku. The energy released from the fight allows Babidi to free Majin Buu.
Despite its appearance, the creature easily kills Dabula and knocks out Gohan and Kaioshin. In an extreme gesture, Majin Vegeta decides to sacrifice himself in order to permanently destroy Majin Buu Final Blast. Unfortunately, however, the enemy survives, leaving the protagonists with the training while Goten and Trunks are ready to learn the dance from Metamor and Gohan on the planet Kaiohshin.
Majin Buu and Babidi return to threaten Earth, so Goku intervenes and transforms into Super Saiyan 3 and manages to hold his own against the pink monster. Convinced by the protagonist to wait for the return of Piccolo, Trunks and Goten who are being sought by Babidi, The wizard continues to give orders to Buu, who is fed up with being ordered, and kills him.
Now free, Majin Buu separates from his evil part, Evil Buu, who manages to repel one of the attacks, thus absorbing the original Buu's energy. The new creature Super Buu wants to fight at any cost and makes his way to the temple of God, where he can finally face it Gotenks. Transformed into Super Saiyan 3, the Fusion features a new technique, the Super Ghost Kamikaze Attack, which manages to break Super Buu into many parts.
So Piccolo decides to do it Imprison the enemy in the space of mind and time and destroy the door. However, once Buu regenerates, he unleashes a scream so powerful that it opens a rift between the two dimensions and returns to Earth. The situation is critical, but Gohan has completed his training by receiving the Unleashed Potential. However, not even his strength manages to overcome Buu's cunning, who, after absorbing Gotenks and Piccolo, once again proves his superiority.
So Goku thanks that Received Potara Earrings as a gift from Kaioshin the Great, teleports to Earth and asks Vegeta to band together to stop Buu. After an incredible exchange of blows, Vegetto allows himself to be sucked into the creature's body to destroy it from within and free his companions. Realizing what is happening inside his body, Buu achieves a new form: Kid Buu, his original form, who defeated three Kaioshin.
Goku and Vegeta immediately intervene, but Kid Buu launches a destructive orb at Earth. The planet is destined for a terrible explosion and the fighters are taken by Kibitoshin to the Kaiohshin's planet, where the Saiyans are free to fight against Buu. Thanks to Neo Namek's Dragon Orbs, the earth is reformed and its inhabitants brought back to life, and Vegeta asks them to raise their hands to send energy. Goku is actually preparing the most powerful Genkidama Sphere in the seriestransforms into a Super Saiyan to permanently destroy Kid Buu.
There Saga of Majin Buu narrated from chapters 421 to 516ends with peace restored to earth and Goku saying goodbye after a ten year time skip.