Warning: This may have a few non-descriptive spoilers.
This manga, as simple as it seems, has more than one layer. One layer is the coming-of-age of a troubled teenager who prefers his supernatural friends (who are very approachable and wise) to any human relations except for his best friend, Hase Mizuki. He often feels helpless when dealing with people, as seen in his former home-life and a few conflicts that come up in the series.
Another layer is about how he grows from a normal human with latent powers into a supernatural creature himself.
The reader slowly learns about the support characters also, mostly about how they
died and what keeps them anchored to Earth.
The art is quite pretty, solidly drawn characters and subtle backgrounds.
If you like supernatural stories such as Natsume Yuujinchou (basically supernatural school-life stories with rather slow plot), give this one a try. As opposed to what the summary implies it is not primarily a romance, the above-mentioned girl is treated the same as any other support character up to now.