Some Mangas, probably most, are flipped to accomodate english speaking readers because in Japan they start form, what to us, is the back of the book. Some are simply flipped and everything is mirror image and some are reordered form back to front and panels are pasted, so that they won't be mirror image. Blade of the Immortal is editted the latter way to the wish of the author, probably because if it was mirror imaged, the hero would have a huge swastika on his back when it's suppose to be a suvastika (similar but pointing the other direction).
Doh, beat me to it, JELEINEN, that's what I get for yapping while posting....