[Rei draws herself up to her full...fairly short...height and stares levelly at Kari. She doesn't want to explain it, but she may as well face that fact fully.]

Kari-chan. Back home, I died before coming here. I'm told by Ami-chan that I come back. I'm...resurrected by Sailor Moon and we go on to fight more enemies and bring back the Silver Millenium. But I don't know if that's true or not. It could be a different world's version of the story for all I know. So, as far as I'm concerned, until I go home and find out the truth, I'm dead.

And that means being here is better than being there, for now.