Disclaimer: only 4 chapters have been published at the time I'm writing this. My opinion might change later, but I have high hopes. Also, I intended this review to be short and sweet, but the minimum requirements by MAL are preventing me from that... But on to the real review!
So far, this manga has a nice touch of the supernatural (hint: look at girl's shadow on the cover), but it's still early enough that I don't know which direction it's going to take. It could be an intensely supernatural manga, or just a source of explanation for one of the characters.
I might be overlooking something, but so far it doesn't seem to be leaning in the direction of "harem" either... However, there's enough ecchi to give the already good story an extra boost of interest. It's not really perverted, and it's not constant, so when the occasional nude happens, it's a nice little event.
The undertones of potentially strong romance are definitely there, and the art is (in my opinion) fantastic.
I can't give too much more than that, other than that this is interesting, and I look forward to each new chapter that comes out. (If this were a "completed" manga, I probably would have binged on it and read it in a weekend.)
I strongly recommend giving it a shot.