Goku and Vegeta set off to train where they’re visited once more by Future Trunks. But, suddenly, Trunks vanishes and the mysterious man ‘Fu’ appears. He says that Trunks is held at the uncharted Prison Planet built between the universes. To be freed, they must gather the Dragon Balls and expect endless, tremendous battles. Will Goku and friends be able to reach Prison Planet and save Trunks?