<When you ride in Japan>
When you ride in Japan you must carry either of following rider’s permit.
●Japanese rider’s permit for those who reside in Japan.
●International rider’s (driver’s) permit issued by the countries which ratified Contracting States of Geneva Treaty in the official format.
●Non Japanese driving permit with the Japanese translation documents of Switzerland, Germany, France, Taiwan, Belgium, Estonia and Monaco.

Reference (Outside link)

■Police Department
http://www.keishicho.metro.tokyo.jp/multilingual/english/traffic_safety/drivers_licenses/index.html
http://www.keishicho.metro.tokyo.jp/menkyo/menkyo/kokugai/gaikokumenkyo.html

■Japan Automobile Federation (JAF)
http://www.jaf.or.jp/e/translation/with.htm