Actually, the first episode is pretty different from the opening part of the manga. Now, it's nothing that will change the overall story (even the biggest change didn't do that), but there were a lot of differences (including quite a few scenes that were cut out for the sake of time). I'll get into what I think about the changes when I write up my impressions on it, but they are definitely there.
All the same, a great first episode, and I love the animation.
All the same, a great first episode, and I love the animation.