The concept isn't particularly mindblowing. It is just another supernatural story but it does achieve quite a lot in its execution. It explores many philosophical and psychological themes--the most prominent ones being time and change. It also presents its own philosophy which I thought was something along the lines of accepting change so that we may attain a higher state of being. One of its episode's take on escapism I thought was quite ahead of its time.
It is a highly symbolic work as many of its elements either symbolise or allude to ideas that have influenced Kadono.
Now moving to the material aspects of the anime, the art and sound direction is immaculate: the OST is as good as it gets and the art and the atmosphere suit the story well. The dialogue and the visual narrative are also very well done; it doesn't try to be too clever for its own good.
As far as the characters are concerned, I believe that characters cannot portray human beings adequately and therefore should focus instead on being more than just characters. That is indeed the case here as characters represent memories, feelings and ideas.
All in all this is one meticulously crafted show that undoubtedly is one of the medium's absolute classics.
