Spoke to AA NRT today to get some info. I did let it known that I'm not actually based in Japan. AAgent said that I can pay for it and ticket on the phone at anytime. He even mentioned that I could've booked the entire itinerary through them - they just fax a form to pax and you'd have to write down desired itinerary and/or flights and fax it back. Admittedly I didn't show him my booked itinerary for fear that it'd somehow screw up, eg "no no u can't have such a long lead time to payment" etc, so maybe there are variables the AAgent hasn't considered. Will see what happens in September when I'm ready to pay.