In all honesty it's probably not available in Japan either...
There seem to be a very large number of sellers with Japan as their location who list identical items - guitars and Oakley sunglasses are just two categories about which I know. I often see multiple listings of the same guitar with identical photos for very slightly different prices with different sellers - check out Brian May guitars or PRS Custom 24 and you'll see what I mean.
So yes, you may well be tempted to buy a Ltd Ed guitar that's not available anywhere else from Japan, but chances are it doesn't actually exist. If you want to risk it then at least you'll be covered by eBay's MBG for most of it - any import duty you pay would have to be reclaimed from either the importing courier or HMRC, though at least if you got as far as paying separate import duty it would mean the item (or, at least, an item...) was in the country.
Personally, tempting though it seems, I wouldn't risk it.
