Compared to most of the phones that Japan is currently using, the Blackberry is like giving stone tools to a technologically advanced race of super beings—it's a nice sentiment, but they'll probably prefer to stick with their warp drives and ninja holograms.
Anyway, DoCoMo may be working on a Japanese Blackberry interface and that the device should be available in 2006. That's assuming that the Email-Reading Robot Union doesn't go on strike when it begins perceiving these handheld as a threat to their way of life.
Blackberry for Japan in 2006? [Dottocomu]