Story - 10/10
The series begins with the dream of a girl falling through the sky, she eventually wakes up and finds herself in a cocoon from which she breaks out, only to be surrounded by several girls claiming to be Haibane, who explain that she is one of them. What are the Haibane exactly? that is something which is never really fully covered even in the show, and that isn't a fault, rather it adds to the mystery of the anime and encourages you to think for yourself. The closest description however would be an angel, they eventually grow wings and are given a golden halo, which the main character soon finds out.
The main characters name would be Rakka, the series shows Rakka trying to blend in with those around her, and illustrates her journey as she comes to know the town in which she lives in, the Haibane are forbidden from leaving, are forced to wear second hand clothes, and live in a run-down building, and while this appears to be discrimination its quite the opposite.
Without giving spoilers, the anime has some quite dark and serious themes, which are addressed by the end, the plot is extremely creative and intelligent, and because of that it might be hard for some people to truly appreciate it, this is an anime that you need to look at differently, and when you do that it really is rewarding.
Animation - 7/10
I can't really fault the animation nor can I really praise it, it does the job and while it might seem a little dated it doesn't hinder the experience, personally I like the animation very much, however I can't justify giving it anything higher than 7/10
Characters - 10/10
The characters in this show are extremely interesting and unique, I can definetely say I'll never forget them, however this series really shines with the relationship between the two main characters, Rakka and Rekki, the character development between these two is outstanding, all of their interactions throughout the series leads up to the final episodes, which is one of the most moving pieces of drama I have ever seen.
Sound/Music - 10/10
I'm going to go as far as to say Haibane Renmei has my favourite OST of all time, the opening is beautiful and reflects the show perfectly, while the ending is unique and really grows on you. Aside from that the BGM is really well done and compliments the scenes wonderfully, the voice acting is also worthy to note, and happens to be very impressive.
Overall - 10/10
Yes, I've given it 10/10, everything about this series is perfect, the only thing I couldn't give 10/10 was the animation, this is however an anime which is difficult to jump straight into, initially the plot progression is slow, fans of action and fast paced anime might feel a bit impatient, but once you start this anime you should make an effort to watch all of it, because the ending could very well change your whole opinion. Once you look under the surface you'll find this anime is extremely well put together, the symbolism is seamless and all comes together, while some people complain of the fact not all questions are answered by the end, I feel these were purposeful omissions, it's an anime that allows you to come up with your own conclusions, and it's not just a cheap way of getting out of explaining things, a simple explanation would in-fact cheapen the show.
As I said, the plot is initially slow, but the ending is more than worth it, it's extremely thought provoking and you'll definitely remember this as a unique and unforgettable anime.