Poker is quite "in" in Japan right now and several bars and cafés arrange home games and tournaments. If you or somebody you know, knows Japanese you should start here:
www.japan-poker.net
http://blog.livedoor.jp/pokermaps/ww....com/japan.php
If not, try to contact someone here:
http://blog.livedoor.jp/pokermaps/
Then again, there is a LOT to do in Japan besides playing poker. So whatever you do have fun!
/Tiggz