This is a really difficult story - it's a complicated mix of mystery, psychodrama and psychological thriller. It's also an interesting study in trauma responses - all these kids are deeply traumatised by their past lives (after all, in order to get to this point they've all had to literally experience death through magic); they're kind of equivalent to Vietnam vets suffering from complex PTSD, only instead of the flashbacks being to their experiences in the other world of war, they're flashbacks to a past life. It's made more complex by the fact that there are people who've decided to play out that past life conflict again in the present, which has the side effect of re-traumatising everyone with new events, as well as forcing them to dig deep into their past trauma to try and figure out how to stop things from exploding into outright war again . . .
And on top of all that is an element of "multiple personality disorder" (using that term in scare quotes because this isn't actually the same as the real world thing we call Dissociative Identity Disorder these days - this is a true separate personality on top of the original one), and it's interesting to see how the different people are responding to that. Everything from being utterly subsumed by the past life (Nishini(sp?)/Lucas being the big one there), through to pretty much integrating the past life with their present personality (Minami - he's had far longer than anyone else to do that, after all), and a whole range of stuff in between. It's dealt with surprisingly well, I think, particularly in the context of the past conflict being reignited - people are having to deal with all the trauma and the identity issues and the fear and uncertainty of the past and the fear and uncertainty of the present, all mashed into one big ball of GOD WILL IT EVER STOP!!?! The biggest failing I can see in the broader characterisation is that not enough of them have just collapsed in a heap and been sectioned (or whatever the equivalent is in Japan).
Still, I kind of wish it wasn't quite so /sloooow/ to progress . . .