This series is going to stick with me for a long time, as something I'd highly recommend to all.
I think I'm going to go back to watch the first episode. And maybe re-watch the entire series.
I think the ending was beautiful. Not graphic/artistically so, but plot-wise. Yes, it left a lot open. But that, I think, makes it really good. And the characters are pretty well fleshed out by the end, which makes it nice too. I don't know, my words don't do it justice.
Interestingly enough, it's only 14 episodes, an unusual number (typically, series run 13, 24, 26, 51 or 52 episodes long...)