HI Diana.

I've nonrevved several times in the other direction but only twice from USA to Japan. Both times I selected Osaka/KIX as my point of entry as that destination always seems to be quieter than NRT, hence easier to get a flight.

I'd probably pick one of the major gateways, like LAX, with several flights a day to NRT, and then get a zed or multi-endorsed ID.
Don't forget there are some *very* unlikely suspects that are options - RG and TG for example fly from LAX to Japan and are often available, where the more likely suspects such as UA NW JL NH etc are heavily booked.