The series is a sequel to Super Dragon Ball Heroes: Dark Demon Realm Mission! It has it own continuity and version of events based upon the original story material that debuted in the Super Dragon Ball Heroes, Prison Planet Saga.

The plot involves the mysterious Fu, who after kidnapping Future Trunks, lures Goku and Vegeta to the Prison Planet, an experimental area which Fu created and has filled with strong warriors from different planets and eras in order to force them into a game where they must collect the seven Dragon Balls if they wish to escape.
Timeline placement

For the Dragon Ball Super characters, the events take place after the Universe Survival Saga. For the "Xeno" characters the events occur after the Dark Empire Saga.