Getting a Japanese Drivers License from Scratch
If you do not have a driver’s license from your home country, or if you did not get your license more than three months before you came to Japan, your only option if you want to drive in Japan is to get a license the same way that Japanese people get their licenses. Unfortunately, this is no easy task. Here are some articles about how to to get a Japanese driver’s license when you DO NOT possess a valid license from your home country.
Two blog posts by a person who got her license in Fukushima Prefecture
Driving Miss Crazy Part 1: Japanese driving classes
Driving Miss Crazy Part 2: Hit the Road, Jack
Article in Alien Times
Getting A Japanese Drivers License From Scratch