First Solar has been looking around the Japanese market for some time, and finally (according to company announcements and various press reports over the past few weeks) is going to jump in, both selling modules and developing and selling completed "mega solar" projects.
First Solar acquired Tetrasun earlier this year, a company that has high conversion efficiency traditional crystalline technology -- a good match (at the right price and other factors) for the Japanese rooftop market. They are teaming with JX Nippon Oil for eventual roll out in Japan. And they announced their first smaller project with existing First Solar CdTe thin film modules. The planned total First Solar investment in Japan is $100 million.
UPDATE: In summer 2014, XSOL announced a supply agreement to import and sell First Solar CdTe modules in Japan.