I really liked the beginning and I thought this had great potential. I picked this because I heard it was similar to a favorite manga of mine called Uragiri wa Boku no Namae wo Shitteiru. And it was, the beginning at least.
At first it started simple, without any confusion. I can tell that until volume 5, it was an 8/10 for me. I was excited to continue, but as the story proceeded, I lost interest and it became super confusing. I couldn't even take some things seriously... The manga has shounen-ai tones, rape and incest. Still, I didn't mind, but I felt bored of the story later. It was all about SetsunaxSara love and it was getting ridiculous at times. I was expecting something more intriguing. I know it is a romance title, but I didn't like the certain relationship. Also, I detected a few plot holes that were never explained.
I didn't like any of the characters. Setsuna was a mediocre character, being all obsessed with Sara and Sara was just... Super annoying. As for the others, many of them are not memorized that well, especially on the beginning. The author keeps introducing new characters without being able to remember the past ones.
Many male characters look like girls and I never liked Yuki Kaori's artwork, personally. She makes all of her characters so similar.
Too bad, it disappointed me. Also, if you are a Christian, you will be very offended by the content, because it introduce Angels as the bad guys.