This is my first manga review and honestly one of my first manga... so apologises if this is structure odd or something.
Story - I won't go into detail here but I loved it.
Art - I don't think I've read enough manga to the point in which the artwork bothers me - but this artwork seemed good here - I am not sure what everyone else may expect, but I thought it was good!
Characters - I loved some characters, some others were perhaps not as engaging or interesting... but Natsuki is by far one of my favourite characters so far! I found Kouta a little unlikable at the start but towards the end I started to feel empathy towards him and I suppose that character development is what the series is about. Chiaki was also an interesting character, Kanade... not as much.
Enjoyment - i maybe biased but as I was reading this on the way to and from work and before bed, I somehow enjoyed this a lot lot more than I thought - gave me something to look forward to!
Overall - I loved it, not a lot more i can say
I hope this review wasn't too awful, hope it helps.