I am not a big anime fan..I watched a lot, but none of them made me impressed like this.I'm really congratulating the writer..I watched all episodes ( including special ova episode ) in 1 days without moving..In next 3 days, I watched two times again..
It has a sci-fi based gorgeous story; if you love thinking on complex stories, this anime is a must for you...It's just 13 episodes, but makes watcher even cry with dramatic scenes....You can taste all the feelings in this series.You can see all the emotions.I had never seen an entertainment that describes character psychologies as well as this.
So my comment is just watch if you didn't yet..The best anime 4ever...
10 points are not really enough for this title, but sorry its max allowed here.