International driving permits can be used in japan during for up to one year. After, or before the one year (or the expiry of your international license), you can change to a drivers license. Depending upon where your international license comes from will determine what you have to do to change your license. Australian driver's license holders need to fill out some forms and do an eye check, but do not need to take a real drivers test. United States driver's license license holders need to take a full test.