Hatsune Miku: Project Mirai will be released only in Japan, and Nintendo 3DS is region-locked. If people from Europe and America can play in the Hatsune Miku: Project DIVA (2nd/Extend) on Sony PSP (because it's not region-locked), then the owners of the Nintendo 3DS will not be able to play Hatsune Miku: Project Mirai. Voaloids is popular not only in Japan. They Have many fans in Europe and America too. So i not see problem in localization.