A wealthy family hosts an intergalactic martial arts tournament on Earth in which fighters from across the galaxy compete including Gohan, Piccolo, Future Trunks, Tien Shinhan, Yamcha, and Krillin. All but Yamcha effortlessly advance much to the concern of Mr. Satan who recognizes them from the battle against Cell and knows he will need to face whichever one of them wins. In the semifinals, Trunks fights Tien and defeats him and Piccolo is annoyed by the lack of challenge and forfeits against Krillin. Gohan, Trunks, and Krillin advance to the finals where they each battle an alien fighter. However, as the alien fighters are revealed, the fight promoter realizes that these are not the staged, fake aliens that he recruited for the event. Trunks is challenged by a sword welding alien warrior named Gokua, Krillin is defeated by a female alien named Zangya, Gohan confronts the mysterious alien Bujin, and another tournament contestant is killed by the alien fighter Bido. Meanwhile, having been complaining of fake stomach pain to avoid fighting, Mr. Satan gets trapped in a transportation pod and sent to the battlefield.

Peace and order have been restored on Earth in the present, but Trunks' future world is still a place of darkness and despair! Once he arrives home, the future will be forever changed!