Yeah, it's a manga. Pretty much the best manga I've ever read.
Very dark, very graphic, and yet the death and brutality never comes forced, it really comes natural for this world. The character of Guts, the Black Swordsman, the Struggler, is the most awesome guy in existance. You've never seen anyone with such a horrific life before who's still constantly pulling through it even though he has the odds so heavily stacked against him that he has gods as his enemies.
I highly recommend Berserk to anyone (apart from kids who might be too young for it).
Oh, and if the art style puts you off at first, don't worry, it gets a hell of a lot better, as you could tell from the first picture I put up.