I just sent something to Avex. I hope it was to the right place: that website is really hard to navigate depending where you want to go. I just filled out an inquiry form half in Japanese, half in English. It says that it takes them 2-3 business days to respond, so we'll see if I get and e-mail back.
Also, I think it's hilarious that they have English versions of artists' pages but don't have an English version of the main Avex page.