The story is 10/10 and is best red with classical sleeping music.
These are my comments.
I feel like it should have ended at chapter 14 "The Struggles of a Replica".
If I were the anime director, I think I would end the story there.
I feel like everything has been done at chapter 14 and because of that, it feels like the chapters after became a normal romcom.
I enjoyed the story a lot really, but after chapter 14, it became bland.
The reason is all the problems seems to have been solved.
Sunao seems to love and care for Nao now and I do not see any plans for revenge against Hayase (The bad guy) I also feel the chapters after 14 became like any school slice of life romance.
I mostly like the story from the drama. Either way, I felt really bad during chapter 11 "Sudden despair" because it really felt like a tragedy.
If Nao did not came back to life, it would make me feel really bad and full of emotions.
If I was the author, after chapter 14, I would continue the drama by indulging in showing the perspective of supposedly bad guy, Hayase.
I would love to know more on what is coming next, as long I can feel the emotion.
NOTE* I bet if I didn't add spaces between each sentence, you would not read it. I think every sentence should be like this. It looks more clean and organized. Thanks for reading!