Slight correction to this:
Japan allows 3 bottles of wine "duty free" and it is 150 yen per bottle after that. You are allowed to bring in as much as you like so long as it is deemed for personal consumption. The rule of thumb is up to 10-12 cases is for own consumption. I usually bring 3 cases a few times a year, go to the "Goods to Declare" line and it is a very smooth and well organized transaction.
Really? On the arrival form it just says 300 yen per 750 ml bottle. But here there are different rates for different types of drink, which makes more sense. But it doesn't list wine so then the 15% for "other" would apply? It makes sense for wine since it can range from $1 to $10,000 for a bottle.
http://www.customs.go.jp/english/summary/passenger.htm
I was going to ship wine from France to Japan but never got around to doing it.