Wow, the immense amount of tweets coming in from Japanese users is not the only proof of what's going on in Japan.
The Samsung Galaxy S is the most sold phone right now (check the news from November). Japanese love it. Amazing, how quick things can change.
I Guess, we'll hear more soon about it, as Android is on the street everywhere. And not only there. If you checked the marketplace recently, you can see some great high quality apps there from Japanese developers. One of it, is "Game Dev Story" from Kairosoft. It's a nice game, with some retro-style and good ideas. It's available in English and Japanese.
But this is only an example of the great things, we can be looking forward to see from the new Land of Android :).