The mysterious Fu kidnaps Future Trunks and lures Goku and Vegeta to the Prison Planet, an artificial arena he has stocked with powerful fighters pulled from different eras and universes. To leave, they must track down seven Special Dragon Balls scattered across the planet while Future Mai, who tagged along, tries to keep them together. Xeno Goku, a version of Goku from another timeline, soon confronts the group, and the search for the Dragon Balls escalates into a wider Universe Conflict arc.