I just spent some time reading The Cutting Edge: Fashion from Japan.
"Just spent some time," of course, is code for "I read it in the bookstore cafe then dutifully re-placed it in it's correct slot on the shelf." I may not be spendy, but as a former employee, I never leave piles of books on tables.
It's one of the few fashion books I've found that has a satisfying discussion of fashion and art. Of course it covers Rei Kawukubo, Issey Miyake and Yohji Yamamoto, plus Junya Watanabe and Jun Takahashi. (Wow, when did I learn to name-drop mouthfuls of Japanese designers?)
I was happy to read a bit more about Hanae Mori as well. I used to own a very sweet smocked dress of hers - vintage 60's, complete with naked fairies and snails.