The only thing I missed in the story was a huge plot twist, because, even though there were some unexpected events, I wasn't put completely off track all at once. However, I did very much enjoy trying to solve the puzzles they're solving in this detective anime.
Another thing I liked, was the art: it showed a lot of detail.
One of the details, by example, is the pupils of Yakumo. If you closely you can see a round pupil in his green eye, but the one is his red eye is more cat like, making it more inhuman.
And this is probably the best thing in the whole anime: there was character development! Oh, do I love character development...
That said, the combination of mystery with some supernatural, good art and character development made this a good anime.
It is the kind of anime you can watch in a very short amount of time, really enjoy, but don't have to become all obsessed over, which is a nice thing, if you have too much too fangirl/fanboy about already in your life like me.
In short, just go watch it.
