Yui is cute. This series has promise.
Delving into the supernatural always seemed to be a lose-lose situation. Either nothing happens and you feel like an idiot or something does happen and nothing but ill comes of it, in which case you are an idiot.
I can understand that the MC has a drive for getting into it but it seems like there would be easier ways to thank a ghost than open yourself up to be a mobile hotel for ghosts, spirits, and demons.