[MMM]

I think GoNative nailed it. This is why a great majority of foreigners working in Japan are language teachers, because they ARE more qualified to teach their native language than a non-native speaker. (That doesn't mean there are no good non-native teachers.)

There are also a lot of foreigners in Japan working in IT. Again, if there aren't the candidates in Japan, or they aren't as qualified, then a foreigner can get hired, even if he or she doesn't speak perfect Japanese.

The two problems I see for you are these:

1) There is a LOT of competition and a LOT of talent in Japan in the video game industry. I think it would probably take designing a game on your own that gets cult or better attention on a smartphone app or Wii's virtual console (like World of Goo or Bubble Ball).

2) Technology is not your friend. I have worked for Japanese companies on video games, (translation) but I never needed to leave my home. Companies like Nintendo don't allow any "outsourcing" for their titles, but smaller non-console companies are more willing to outsource more. So you may be able to get the work you are seeking, but it doesn't mean you would necessarily be moving to Japan.