This movie takes place one year after the Buu saga. King Kai tells Goku and Vegeta to come to his planet right away. Goku uses Instant Transmission to get them there. Vegeta asks what King Kai wants. King Kai says "Well I have some bad news. Bruss is in hell, like he should be, but he's destroying everybody that he sees. Normally just one of you could beat him now for sure. But he has gone Ultra Saiyan 2!!! This form is 50x times as strong as his base form which as you know is a Ultra Saiyan. Plus, to make matters even worse, he has mastered the power to form an energy moon and go ape on his own since there is no moon in hell. He might be unstoppable."