Six childhood friends grew apart in high school. One of them is Jintan, now a shut-in. He gets a request to fulfill a wish for Menma, the only one of their friends to have stayed the same over the years. In order to grant her wish, he will have to find and reunite their old friends.
I can't fully describe just how amazing this anime is. Story wise, it's a drama, and is full of very sad moments- I found myself holding back tears several times, but at the end I just couldn't hold it in and bawled my eyes out, haha :P (However, there are brief (yet perfectly placed) times that are funny. - So it's not just a sad sad sad story.)
Although it's 11 episodes (complete, unlike it says here) - It doesn't feel at all too short. Brilliantly written and very well told. The animation and dialogue is top notch as well. Music is very suitable, and never feels out of place with the scene. All of the (main) characters are totally unique, and going through the series learning each one's story and eventually how they all link together is simply superb!
Slice of life & Drama (i.e; Clannad) - If you like the genre, do NOT miss this anime. Please watch it, you won't regret it.