Square Enix has announced that they will launch a console version of Diablo III in Japan. The Japanese version will be sold on PlayStation 3 platform in 2014 and the price has not been decided. At that time, Square Enix will collaborate with Sony Computer Entertainment to make Japanese text and voice.
While Square Enix is best known for their RPGs, they also have a second label called Extreme Edges that localizes Western games for Japan. Most of the Extreme Edges games are Activision titles like Call of Duty or Eidos games. Add Diablo III to that list because Square Enix announced they will publish the console version in Japan.
Diablo III is localized and sold on the PC in a number of other Asian markets, but the game has not been available in Japanese. The Extreme Edge division of Square Enix has published other Western games, and will be providing a full localization effort for Diablo III.
This Japanese localization is scheduled to be released only on the PlayStation 3 console. The Xbox 360 console has not sold well in Japan, so it may not be worth it to bring a localized version to that console.
According to the official Diablo III Console FAQ, the console version of Diablo III will eventually be available in South Korea, Taiwan, Hong Kong, and Southeast Asia.