From the introduction:
Welcome to planet Earth, Jumper, but very different from the one you know. It’s part of a much bigger galaxy, of tyrants and near-extinct monkey warriors. The adventures of Son Goku seem to have concluded and he has settled down with his wife Chi-Chi and his new son, Gohan, named after his grandfather. However, in a few months, a space pod will arrive containing Goku’s previously unknown brother Raditz, who will reveal the truth of his origins and start a chain of events that will escalate into struggles between powerful warriors and monsters alike. And that’s when you come in. The year is Age 761, and you will be spending ten years in this world, which would bring you to four years after the Cell Games if you do not change this world’s history. Perhaps you’ll be here even longer than that. Go, Jumper, and train hard!