Japanese SIs using Drupal

As background, I speak Japanese and have lived in Japan for a total of four years in the past. In my past career, I've worked pretty closely in building software businesses in Japan, mostly by working closely with the large systems integrators like NEC, Hitachi, and Fujitsu.

Today I met with a representative of NEC today and gave him a briefing on Drupal and Acquia. He was in the US gathering information on interesting Web 2.0 companies and technologies. NEC is one of the top systems integrators in the Japanese market. They develop their own application stack and offer solutions on top of it to the largest clients in Japan. We had a lot of success with Flex in Japan as a direct result of their early investment in helping us take the technology to market.

We had a good introductory discussion, but I quickly realized how little I know about Drupal adoption in Japan. It would be great to hear from some of the other folks here about what they are seeing in terms of Drupal usage in Japan. I found drupal.jp and it seems like there is some reasonable level of activity, but not as much as disproportionately less given Japan's large market size.

Are any large companies in Japan using Drupal? Is the community well organized and functioning? Are there any Drupal books in Japanese?

I'll be posing some of these same questions in the drupal.jp forums, but figured it might be interesting to start here. Please help me get up to speed.