It absolutely makes sense, but I'd get working on passing the road test as soon as you feel comfortable driving in Japan. There's a whole "driver's license industry" here where drving schools charge from 300,000-500,000 yen or about $2,900 - 4,800 US to train students how to drive and most importantly, how to "pass" the test. It's a cozy relationship between the DMV and this industry, so they really frown on people taking the test without enriching the industry first. Just like Bancherd, it took me 3 tries to pass the test, and I'd been driving in Japan for at least 9 years before they changed the law.

They will focus on small mistakes and use these as a reason to fail you the first few times around, so don't get too upset if you don't make it the first or second time around.
On a separate note, I went to get an international driving permit from the DMV here in Japan when we visited Hawaii last year, only to be told that I could drive in Hawaii on my Japanese driver's license! Seems like there's no reciprocal agreement for Hawaii residents in Japan though...
