I don't know who you were talking to, but all my NRT-based flights have been ticketed by the TYO sales office with a U.S. credit card. I did the last one 2 weeks ago.

I will typically call TYO after their business hours. If I do, the phone system, when you listen to it, will actually allow you to connect to an agent. After hours in TYO is daytime in the U.S. The call routes to the Japanese desk in DFW and I have never had a problem ticketing with my US-address credit card.