Contact Tak
You can contact Tak through Zero's, his Action Team agency.
Address (in romaji): 150-0031 Sakuraoka-cho 22-17 Grand Spot 503, Shibuya-Ku, Tokyo - Japan
Telephone: 0081-03-5489-8621
Fax: 0081-03-5489-8622
Email: contact@dongyu.co.jp
Otherwise, you can fill out the contact form in Zero's official site: here it is.
You can also write him a message through his official MySpace, or if you know some japanese you can leave him a comment in Zero's Action Team blog.