|The most respected, and only, Japanese artist I know of on the international scene is Murakami. I just saw an exhibition in Boston: http://www.mfa.org/exhibitions/takashi.html|
I don't really like his stuff and tend to believe his philosophy to be bunk. As for the manga question. Look at woodblock stuff and look at any manga - my guess is you'll find one to be "art" and the other not strictly based on your conditioning to think so. Murakami's art looks like "really nice" manga or what I imagine an anime cell looks like. Also, if you doing a paper he has written in length on the Japanese athtestic, contemporary Japanese art, and his own work in the essay "Theory of the Superflat" or something like that.
Email me if you want some more links, though there arn't many, or want to carry on this discussion at length.