The driving test itself is not difficult, but there are many simple sequences and processes that the test proctors are looking for, and if you are not aware of them, you will not pass. It is not uncommon for foreigners to take the driving test 6 times or more, simply for the lack of a little knowledge, rather than a lack of actual driving skills. Passing the first time, un-assisted, is the exception, rather than the rule. Considering that each attempt requires nearly a full day at the testing center, fees and lost wages can make converting your license on your own a time consuming, expensive, and frustrating experience. The average pass rate for Tokyo (unassisted) is 35%, and for Nagoya is 20%.
The procedure at each driving center varies, so please be aware that your specific location may be different from what is detailed here. On the test day, be sure to show up as early as possible. Usually, you are allowed to walk the course beginning one hour before the testing begins. It is highly recommended you take advantage of that time to walk the course, and refresh your memory of the route and the skills they will be testing for. Depending on the license center, you may be required to pay an additional car rental fee. You will most likely spend a lot of time waiting on your driving test day.
When your turn comes, you will be required to get in the car and drive the prescribed course with an examiner, who will speak only in Japanese. Their commands are very simple or non-existent; many test centers do not give any instructions, other than to start. They expect you to have the course memorized. With some basic knowledge of Japanese (left, right, stop, go, etc...), you should be OK if the examiner does give you instructions. However, it is best to memorize all the turns and elements of the course in advance so you will not necessarily need to understand all the proctor’s commands.
If you make a "major" mistake you will fail on the spot. The test proctor may tell you its over at that time, and instruct you to return to the starting point without finishing the course. If you keep driving he will assume you do not understand, stop the car using his own brake, and direct you more clearly to return. Do not worry, you are not in trouble (you just failed)!
Whether or not you passed, you will be instructed to go inside and wait for the results with the other test takers. This may take some time. If you were not successful, you’ll be given a paper with your next scheduled test date. You may be able to change this schedule on the spot or over the phone later, if required.
If you are successful, you should receive your new license that day. This will entail paying more fees, getting your picture taken, and other assorted tasks.