What it is on the surface: school kids and random weirdos fighting and hunting ghosts. What it really is: interesting, creepy, charming character driven work that slowly builds up tension to the last few episodes.
Mai is a girl who accidentally breaks the camera equipment of Kazuya--a ghost hunting mystic. Kazuya uses this as an opportunity to hire her as a gopher for his paranormal research agency who consults various mystics and spiritual mediums (from a monk who's hardly ascetic to a priestess who seems a total fraud).
The story takes an interesting revisionist view of the paranormal--attempting to debunk the existence of ghosts by scientific means to the existence real, and scary paranormal occurences (usually inspired by true events in Japanese and European history) which is also where the show gets its mixed spirituality from.
It starts out mundane and harmless enough and keeps raising the stakes as the threat and ghosts become real and honestly the atmosphere and audio actually make the show have a very nervous and scary feel to it--without ever having to rely on gore or violence. There's a good blend of comedy and clashing personalities and Mai and Kazuya are good characters--even if the supporting cast is not that original, although they are all given a chance to shine and a human element in the final few episodes.
A few filler episodes and stumbles here and there take away from a perfect score, but this is still worth watching.
