You can get an international Driving Permit (IDP) from Japan based on your Japanese driver’s license. The permit is valid for one year from the date of issue and must be used in conjunction with your Japanese license.
The process takes less than one hour, and requires a visit to the license center in your area during office hours; generally Monday-Friday from 8:45-12 and 12:45-3:00 pm.
These instructions are tailored for Nagoya, but they are generally accurate for Japan more broadly. You can read a location generic version of these instructions here.
You Will Need:
Japanese Driver’s License
One photo, about 5 x 4 cm (the photos from the machine at license center are fine)
Inkan (this isn’t necessary for non-Japanese, but if you have one it is handy)
At Hirabari License Center in Nagoya:
Go to Window 1 to buy your application. Ask for a “Kokugai Menkyo (国外免許)”.
Fill out your application; there are sample applications on the tables near Window four.
Go to Window 4 and give them your completed application, license, passport and photo.
They will give you back your license and ask you to sit down; in about 15-20 minutes they will call your name at the window.
Go back up to Window 4 and you will receive your IDP and passport. You will need to stamp the application form with your inkan to show that you have received it. If you do not have your inkan with you they will ask you to sign for it.