Just finished a random anime I came across. I had my doubts about it at first, but I am thoroughly impressed by it. Great plot, a few turns here and there, and a well thought out design. My only complaint was the lack of action in its fight scenes, but that matter is trivial compared to the rest of positives this anime has.
Currently runs 2 seasons, Tegami Bachi, and Tegami Bachi REVERSE. Both are in English or Japanese with Subs, for those with a preference to either.