What to read after Gantz?

"What would you do if you were given a second chance on life from a catatonic man stuffed inside a computerized sphere? Well that's exactly what the survivors of the first round of Gantz's wicked game have to figure out. Kei, Masaru, and the buxom Kishimoto try to reinsert themselves into their old lives. However, before any of them begin to take comfort in this fact, they're all transported back to the inescapable condo where the whole mess started. Then a new group of civilians are added into the mix. In the disorientation of the new arrivals, Gantz spills the beans on their new alien extermination target. Now, the stage is set for the next round of Gantz's little contest, but how can you win a game if you are already dead?"--Publisher's web site.