Well I'm unsure, I'm no expert on japan domain names but here is a bit of an off topic thought.
I know that the Japan market and basically Asian overseas market has been growing extremely fast in the past few years, and more and more computers are going online over there, I could imagine the lack of quality Japan sites, I'm sure there are lots of quality ones but if you could write a decent page in your own language and convert it over and target that part of the world it may yield some good results.
I'm sure your already aware of all that, hence the .jp domain name but its interesting to think about how much of an influence they could have on the market.