There's no denying the accessibility and freedom of the Japanese railways. They're everywhere, and they're usually so convenient. You may have more options in terms of transportation in Japan, but each come at a pretty high cost. For example, let's say you want to travel from Hiroshima to Tokyo:
1. Four hours and about ¥18,000 by Shinkansen; you also have the convenience of taking any train you choose, as long as it leaves the same day.
2. One and a half hours and about ¥30,000 by plane (unless you book 28 days ahead of time). The money saves you the trip on the rails, but it's hardly worth it in this case; you have to take the airport shuttle with additional time and cost.
3. Of course, no ferry goes between Hiroshima and Tokyo, but even if there were, I'd question the sanity of someone choosing a long distance ferry over air travel. Take the ferry from Kagoshima to Naha, Okinawa – 24 hours, and the same price as the 1.25 hour flight.
4. Driving. This is the topic I want to address today. Naturally, you have the convenience of leaving whenever you want and choosing your own path, but is it worth it? Over a long distance, the tolls can add up to as much money as the train fare.
Let’s say you have been in Japan for some time now. You have a valid driver's license in a foreign country, and would like to exercise the same mode of travel in Japan.
One issue: you can’t apply for an International Driver's License. These are generally issued to newcomers in Japan, and I believe you can only receive them before you enter the country. Regardless, once you have spent three months in Japan, you are no longer eligible to receive an IDL (not without leaving and coming back in on a new visa).
However, you do qualify for a Japanese driver's license, using your old foreign DL as collateral.
Procedure to Obtain a Japanese Driver's License
1. You need your old license, as well as certification that you stayed in your country for at least three months after it was issued. If your license doesn't include the date of issue, you must obtain this certification as well.
2. Japanese translation of these documents, translated only by an official embassy or JAF office.
3. Gaijin card
5. Photo 3x2.4 cm
6. ¥4,250 fee
7. Your IDL, if you ever applied for one
8. Following the receipt of these documents, you will be asked to perform a written test (10 yes/no questions), and a driving test. Although the written test will be in your native language, the driving test may not necessarily be – bring a translator just to be safe. You can forego these tests if you are a citizen of certain foreign countries (I believe the ones that also drive on the left side).
In my opinion, it usually just isn't worth the trouble unless you reside in an area without convenient access to JR or a bus; you have to consider the trouble of purchasing a car in Japan, and then reselling it when it comes time to leave. Of course, if you're considering permanent residency and have younger family members to worry about, then by all means...
But as far as the short-term Japanese resident goes, you won't be buying a car. The procedure to apply for a JDL is lengthy, and in the end, you might only use it for the occasional vacation rental. Still, sometimes, that future convenience is enough to undergo the present inconvenience.