Thanks for the great advice. I'll encourage her to read up more.
She doesn't speak much (any?) Japanese. She's tried learning on-line, so she probably has a small handful of useful words, and she practiced some writing. She did ask for a language-on-tape series to listen to for the next month.
I don't know how much current culture she knows, but she's prepared for differences and she's expressed an eagerness to watch and learn all she can there. One of her close friends is Korean and she's spent nights at her house with her Korean parents, so she's very aware that cultures can be very different, and another American friend of hers grew up in Taiwan, so she hears about that first-hand, too. She's also a huge fan of anime and manga which causes her to follow lots of Japanese bloggers and youtubers. She did a big literature project on a book about ancient Japanese culture diving in for many weeks to produce a 50-page treatise on it. Plus I've been there, if only for 3 weeks. So all that adds up to "she's not afraid to explore and discover differences," so I'll encourage her to do more of that.
I don't know how much flexibility she's have to ask for sights to see, but It will be a good idea for her to know some and ask about them.
I really appreciate the tips! Keep em coming.