Only Osana Rumia, Touhou Maze and one other Anime made me cry like this... Damn it that end was such a twist...
If the series was longer it would've been one of the best animes that is not based too much on battle
Personally, I find having only 13 official episodes, 2 OVA is a lot better than being dragged longer. Of course, I want to know more in the Anime too, and even Maeda said he wanted it to be longer. But well, there's such a fear that longer will just make the story less interesting, like with Bleach and Naruto. Those 2 series got me so tired of them that I haven't even checked them for a long time. And Meitantei Conan too, too long, not good.