One of the best manga I've ever seen. Maybe even THE best one.
The story is told in such a beautiful and poetic way. The atmosphere is different from anything I've seen before.
When I finished it, I was legitimately in awe and that's no exaggeration on my part. It made me think "Wow. This is art". And I can't think of any other series that has made me feel the same.
There are many amazing series out there that have impressed me and amazed me in different ways. But this one did it in a very unique way.