After kidnapping Future Trunks, the mysterious Fu 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.
There are too many cameos and happenstance plot moments for my taste. On top of that, it's jarringly fast-paced and situations aren't explained nearly well enough. There are almost constant clashes and fights, but the choreography and sequencing leaves a lot to be desired. The artwork is quite ugly, though perhaps I only think that because I'm comparing it to Akira Toriyama's artwork. Features will look flattened and misproportioned. The characters are stiff and there's an overreliance on action lines to try to make up for that. The motives for basically every character are ill-explained. All in all, this manga comes across more like fan fiction than a serious series. In fact, the more I think about it, the more upset I'm getting at how sloppy everything was. This was a bad, unentertaining series and the only fair score I can think to give it is a 1/10. Even a 2/10 feels like it would be generous. Think of it this way: if this had been my first introduction to the Dragon Ball franchise, I would have been left with a horrible impression of the characters, the world, and the storytelling in general and would probably never want to pick up another Dragon Ball comic ever again. For reference, chapters 1-5 is a storyline about a prison planet, with Cumber being the main antagonist. And chapters 6-12 is a storyline about protecting various universes, with Hearts being the main antagonist.