I loved the idea of this book, origami, interesting magic ect. All things I normally love in books but it was missing something. 
The plot seemed rushed without enough time to actually grow attached to the characters or flesh them out.

the betrayal at the end had no good reason why other than shirakami are not real people  and don't deserve respect. Which is weird considering the whole book proved otherwise. There was no resolution proving that ideology wrong either. 
There was no resolution at all. It felt like they cut out the last third of the book. I could see it working if it had a page saying next book coming out soon but otherwise it was like driving along a road only for it randomly stop in the middle of nowhere.

Edit: Saw there is going to be a sequel but it was still missing something though it could be because I'm used to the older side of ya. I suggest you read it if it interests you, it's just personally not my thing.