It was a really good story. There was good character development. And relations between the Nagi and Aoi just leaves you begging for more.
Which make the ending so disappointing! It could have gone on for so much longer!!! That is why it is so frustrating. It just leaves you basically saying, "They will end up together in the future at some point."
I was literally yelling at my computer because I couldn't accept that that was it. It was truly sad.
It was a great story with a poor ending. I would only suggest this if you are prepared for disappointment.