Try - Little Boy - The Arts of Japan's Exploding Subculture. Edited by Takashi Murakami.
I recommend it because -
Takeshi Murakami talks a lot of sense. Plus most of the contributors carry some sort of gravitas.
It has some beautiful pictures (!)
It is in full English and Japanese.
It does not make the Japanese Popculture = manga/anime error!
Anyway - it starts as a discussion of key concepts and medias in japanese subculture and then moves on to specific essays on various themes. So in this fashion I think it would be a good read for those who know quite a bit about Japan as well as those who don't. It should help people get past a couple of misconceptions about hentai, moe and WWII at any rate.
I have not finished it, but it has got me thinking about some new ideas and got me interested in some more Modern Artists - which can only be a good thing. It does sometimes go down the old "define-otaku" route that many modern pop essays focus on but at least it does so with some gravitas.
At any rate - it is a good collection of thoughts that verge on academia with some wonderful illustrations. Osusume!