Every once in a while I find a manga that restores my faith in the medium and keeps me from giving up on fiction altogether. Dainippon Tengutou Ekotoba is one such series.
Something that's always bothered me about supernatural beings in fantasy fiction is that, despite their powers, their unusual upbringing, and their very genetics, they somehow end up thinking and acting exactly like your average human, since obviously the author and the readers are themselves human and have no interest in anything that doesn't behave as such. Not so in this story: the tengu, despite actually being (as I see it) a metaphor for extreme cultists, behave just oddly enough that it's not possible to forget that they're supposed to be different from the masses, but not so oddly that you lose all interest in them.
The plot isn't something you can just breeze through without a thought; clocking in at ~920 pages total, there's actually a lot to think about here with regards to the purpose of life and the mentality of those who seek to be "different." I'm a bit of an oddball myself, so I was worried that it would turn out to be propaganda for "the beauty of normalcy," and in a way it was, but I couldn't bring myself to be annoyed: the presentation of the concept was excellent.
I really don't understand why some people complain that the story is confusing and the characters are difficult to tell apart; even if you just read on the surface without bothering to think at all, the sequence of events (though not the underlying meaning) should become immediately apparent, and all major characters have distinct looks, personalities and goals. I rarely care for female characters in fiction, but Shinobu was quite likeable, and very well-suited to being the protagonist of a story like this one.
The artwork is unique, which is as it should be since the plot and characters are much too unusual to fit with a more typical style. It is difficult to comprehend the action sequences, though.
If you're tired of the same-old, same-old, and are willing to expend a little more time and thought than a four-volume manga would typically require, Dainippon Tengutou Ekotoba is an excellent choice.