Potential spoilers in my review, so please read at your own risk.
This anime is utterly gutwrenching in despair, if you like sad sad movies, this is for you. The main character, Asura, a boy who is as feral as the wolves in the woods struggles to learn compassion and humanity, or at least enough to be saved.
The supporting cast, The Monk and Wasaka aide him in learning how to trust people and what is and isn't acceptable for humans to do.
Contains copious amounts of blood, cannibalism, despair, starvation and death. About the only thing I have seen like it was Grave of Fireflies. Still a great movie.
The metamorphosis the main character, Asura, makes is astounding, the development is gradual and comes with a very forceful hand (Literally and figuratively once you watch it you will know what I mean by this).
The animation is very very smooth and the scenes are all very bland and depressing, but it aims for that, not a nock against it in the slightest. The story is complex enough to not be linear, and not too complex to lose the simple minded who do watch it. The soundtrack was phenomenal and fitting.
I recommend it if you like character driven plots.