I'm guessing the Gantz Room because it doesn't seem like the mangaka to just let Kurono go like that.
I understand what you mean and it's also a possibility, but we still have some stuff to see in the Gantz room. It'd be too weird if Kurono showed up in the real world that fast (and we don't even know if that'll really happen).
If Kurono does get transported back, maybe we'll get to see what it looks like to get transported in first-person perspective. Gantz is probably going to do the escalating body-part transport again, but that would be fun to see through eyes too.
where ever it is. kuronos gonna be there and thats all that matters. everyone wants to know how his characters is going to develop. but it probably start in the room cause transport hasn't started.
It must be gantz's room