You haven't? Japan has been under the rule of Chuuoku for some time now, it would be impossible not to know.

[ The wheels are turning in his head. The whole world is different because of WWIII. He has no idea how someone couldn't have heard of it unless they're from a different planet.. but he's familiar with Japan and America. But he also thought Japan still had the Defense Forces... Hmm... ]

Different cultures can be jarring. I spent a significant time in the Amazon and other countries.