Just found something interesting and kind of dumb. Say my phone number in Japan is 080-1234-1234. That's how friends in Japan would have my number in their phone. Unfortunately iMessage and FaceTime format the number in the international format of +8180-1234-1234 and you can't change it. As a result, it doesn't think I can iMessage any of my friends unless I enter a second number in their contact information in the international format. You would think Apple would code it to recognize both in this day and age where people back home will have the +8180 and friends here in Japan will have 080.