look at the photo, it still has the Japanese input button, I say that its just a localization change is all. Short answer, yes its english, no not 100%. But dont worry the apps that you will use that have japanese in them can be replaced by other "better" apps.
Personally I recommend streamlinecpus, they have warrenty help if you need it. If you dont need it and cas is an issue go to pricejapan. But like I said the service is exceptional over at streamline.