*nods*
Actually I didn't see it that way. I agree with you about the reason the trio remains missing, but I wouldn't go so far as to place whole St. Luminous into another plane of existence. The way I took it was rather that the school is a special place (who would have guessed...) helping the girls to find their way/get over the past, but otherwise rather mundane. It also strikes me the most important thing making St. Luminous special is the hero himself, and before him his grandfather. The graduation ceremony is this context is IMHO just that: graduation, but of those who overcame their traumata thus not being disappeared.
Your guess is as good as mine... ^_^
I second this!
The Grifter