If your license was issued in one of these countries;
Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Norway, Portugal, Spain, Sweden, Switzerland, The Netherlands, The United Kingdom, Australia, New Zealand, Canada, Taiwan and South Korea.
And you can prove residency in that country for a minimum of 3 months after license issuance you are not required to take either the written test or road test to convert your license.
You must apply in person to the driver’s license center in your prefecture. A high level of Japanese ability or native Japanese speaker accompaniment is strongly recommended.
I am not required to take a test.
If you hold a valid driver's license from a country not listed below,
Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Norway, Portugal, Spain, Sweden, Switzerland, The Netherlands, The United Kingdom, Australia, New Zealand, Canada, Taiwan and South Korea
And can prove a minimum of 3 months residency in the country that issued your license, after your license was issued, you may be allowed to convert your license only after filing paperwork, taking a short written test, and passing a driving test on an enclosed course at a Testing Center in your prefecture.
I am required to take a test.