<p>Congratulations on your interview, Kosuke.
Have you tried looking up his address in the phonebook or on switchboard.com?
If he told you where he worked, you also can send a thank-you there.
If you get in, give him a call, and thank him again. That follow-up call could be a good time to ask additional questions (which you might have once acceptances come in and you have some choices).</p>