It is a Shinto tale, so some researching could be useful at times (there are quite a lot of references, although not knowing the legends behind them doesn't necessarily preclude enjoyment of the anime) - it's really multi-faceted, though... even if it mythologically makes little sense, one can simply view it as a coming-of-age tale, as ultimately that is how it turns out... it is by no means conventional, and while some viewers might focus too much on the relationships of the characters to the exclusion of the surrounding narrative, in this instance their interactions are a crucial part of the storyline, as there was, throughout the series, a certain political struggle within the school... that was rushed, but the twelve episodes did in the end surely develop the main character.
The ideas presented, though, I think are the interesting aspect of the story here... one might be confused by them, but from an imaginative point-of-view, and with what limited explanations there are in the twelve episodes (and there are, even if viewers drop the anime after becoming very confused indeed) - concepts from having different ('spiritual') 'phases', to dancing to specifically access the subconscious, as only once suggested by a character, to summoning a spirit (unconsciously) due to loneliness - all understandable ideas (but, as this isn't a documentary they don't go on very long about them, which is why a curt or oblique explanation may be frustratingly confusing).
Ultimately, I don't think it was at all not done well... only twelve episodes, another season certainly useful, but the twelve existent episodes felt to me like they could be self-contained, although more of it would be nice...
