Ok, I will keep this vague so that I don't ruin the end for anyone who hasn't see the show. I just watched episode 24 and it was great, plus they finally started to explain some of the things that have been bothering me for a while. Having said that there are so many unanswered questions and so much potential for a second season that I really hope we get one.
As of yet there is now official word on a season 2 but there are currently 13 volumes of the light novel series on which the show is based and the anime barely covered any of it. So here is hoping!