Have you visited Okinawa? I may have missed it in your post but re-reading it a couple times, I don't see it mentioned.

Okinawa in November averages about 75 degrees F during the day, which combined with the tropical humidity can actually feel pretty hot. Nights should be comfortable, though. And it feels enough like a foreign country, and a place distinctly different from "mainland" Japan (with its own food culture), that I think your wife would be satisfied. If you're lucky and there's not a huge box jellyfish invasion, you might even get some beach time in.