The art style is definitely not for me, and I found it incredibly difficult to distinguish between the characters.
That said, this is probably the single most realistic story I've ever seen depicted in manga.
Terrifyingly real. Perhaps... too real.
It's about body perception issues, it's about growing older, it's about the whims of emotions, it's about the fluidity of sexuality, it's about self-worth, and, most of all, it's about the ultimate purpose in life and the many varied paths through it.
I'm going to give it a 9/10 rating, do my best to forget everything about it, and never read it again.