I don't believe they are sold here. I moved to Tokyo 6 months ago and I've never seen another one. (Though I do know of one other guy with one). Never seen any ads or anything in shops either. The XJR is around though.
So these will be one of those export/import jobs that seem to happen here.
I originally understood there to be a 750cc limit on domestic bikes, but then I saw some cruiser type over that size at a dealer.... so not too sure on this.
There are tons of 400cc bikes here, because the licensing cut off is basically like:
50cc - car license
up to 400 - mid range bike license
over 400 - oogata license, or big bike license.
(i could be wrong, haven't been here all that long to sort this out yet).
It is really expensive to go to classes to get the licenses above.
The real cost is over 250cc, where you have a bi-yearly 'inspection' equivalent that runs in the hundreds of dollars. domestic bikes have a 3 year grace period, imports have to have it right away.
if you are moving here, DON'T import your bike. It cost me several thousand dollars to bring in the FJR from the UK.
but there are plenty of dealers here who do the import stuff and package it into the costs. so most all bikes are probably a couple/few thousand more new than in the US. about the same as UK prices though (which are high btw).
-colin