How do I obtain my Japanese friend's address so that I can send him a letter?

Question:

I need to send a letter to my friend in Japan but I do not know his address, all I know is that he lives in Kawasaki City in Kanagawa Prefecture. Is there some website I can go to that will give me the information I need? Is there a Yellow pages/white pages for Japan?
Please help!
Thank you!

Answer:

You need to ask your friend for his address.