here is his official site where you can e-mail miyavi. just click on fan mail
http://www.o-re-sa-ma.com/miyavi/miyavi/index.html
you can read his diary as well(for me i can only read parts of it ;.;)

http://www.masakarasu.net/ this is a english fansite that has translations of the diary as well as other stuff

a pic just for you readers