This is a problem that is only going to get bigger. Just wait until you get the Chinese on the case as well.
They are bandwidth leaches and push 99bb.com over the 3 gig mark !!
The majority of Japanese "traffic" sites do not offer free content in the form of galleries. They tend to right reviews to intice the surfer in, however, I am noticing more and more are hotlinking Western galleries. Asian,Teen and blondes being the most popular. I dont think there is too much you can do about it.
jah