Really nice blog on Japanese knives by a friend and customer of ours, Eien Hunter-Ishikawa. He's a professional musician, specializing in Japanese percussion instruments (taiko, etc.). We met when he was in LA performing some years ago, and it seems he has steadily gotten more and more into Japanese knives. You can check the blog out here:
http://www.eienhunterishikawa.com/blog/interview-jon-broida-knives
http://www.eienhunterishikawa.com/blog/interview-jon-broida-knives