Such an incredibly moving movie, so sweet, sad, funny and just an emotional roller coaster all around. I've seen the animes series and I was a bit annoyed at all the unanswered questions. The series is great don't get me wrong, but I hate not understanding a plot point. LoL And well the movie differs just enough from the anime to explain all those points yet not lose your attention by thinking this is a completely different show. ^^ So I highly recommend checking it out, even with the different anime style and voice actors than from the TV series.
See some Samples over here.
Once again if you don't know the rules check out under my User Info they're all listed there.