It's the best manga I've ever read. And I've read a LOT of manga, from greats like Dragon Ball to I-only-this-read-for-the-sex-at-the-end like "Idol na kanojo to otaku na boku to". The fact that there hasn't been any good medium about Go since Hikaru no Go tells you all about how good the authors were at turning the boring game of Go (it's not actually boring) into an award-winning manga that brought in a massive influx of new players to the game. Oh man it's just so good. I think I might have an orgasm just thinking about it. Story: Perfection. Some might say it could goon a bit longer though.
Art: It's the artist for Death Note. He good.
Character: I have to deduct one point here because of the lack of female characters. Even the two main females aren't as developed as the other characters.