The good news for GungHo is that Apple in the US immediately featured Puzzle & Dragons in the games category:
An Android version in English is in the works, too, if I interpret one of GungHo America’s tweets correctly.
The company also just released a Puzzle & Dragons trailer in English:
Puzzle & Dragons passed the 3 million download mark – in Japan and on iOS/Android only – just two days ago. It’s the most popular social game in Japan that’s not using the Mobage, GREE, or Mixi networks.
It uses Game Center instead, which is probably one reason it got featured by Apple (Puzzle & Dragons uses Game Center in Japan, too).