The brother duo Abo and Kado attack Planet Tech-Tech before following Tarble and his wife Gure to Earth. Tarble requests his brother's help in defeating the two, and Goten and Trunks fight the brother duo, with Goku landing the finishing blow.
The Z Fighters are all gathering together to go on a camping trip, however Pikkon arrives from Otherworld to request the Z Fighters help as there is something wrong in Hell and reality is messing up. Goku and Pikkon head to Hell to stop the problem, while Vegeta, Krillin, Goten, and Trunks head to look for the Dragon Balls.
Due to Janemba being reborn and messing up reality and causing the dimensional walls to collapse, Frieza, Cooler, Cell, and Broly all manage to leave Hell and return to life. Frieza, Cooler, and Cell begin looking for the Dragon Balls while Broly continues his goal to kill Goku.
Future Trunks later ends up in the present time due to falling through a dimensional portal, and Teen Gohan is brought forward from his time.
The Z Fighters combat the revived villains, and Janemba multiple times, until eventually they stop Frieza from obtaining the Dragon Balls and manage to cleanse the planet of evil energy. Goku, Vegeta, Pikkon, and Kibito Kai go to Hell to finish Janemba, and also defeat Majin Buu along the way.