* Bring lots of cash -- charge cards aren't taken everywhere, and most cash machines don't accept international cards.
* Converting some currency at home will save waiting time in a long queue at Narita Airport. In San Francisco, try AFEX on Sansome b/w Pine & California, or buy some yen at SFO.
* Buy a train or bus ticket after you exit customs in Narita -- unless you're staying at a hotel in Narita, taxi fare is too expensive.
* Shoes aren't worn indoors in any traditional Japanese home, restaurant, or ryokan (inn), or outside on wood decks of temples. Hiking boots with long laces will be a nuisance if you're visiting lots of temples.
* Don't soap up in the tub in a communal bath at either a sento (public bath) or ryokan. Use the faucet and bucket nearby for your bathing PRIOR to entering the bath.
* Don't blow your nose in public.
* Bring more business cards than you think you will need. Don't write on other people's or put in your back pocket when they are present.
* Bring toilet paper if you think you may need a toilet outside of the office, also a hankie for drying your hands.
* Bring warm clothes if it's winter, and synthetic fabrics that dry quickly if it's summer. Siberian winds can make cold winter weather, and summers are hot and humid.
* If conversing in English, don't assume people nearby don't understand you. English has been a required course in Japanese schools for some time, and although most are reluctant to speak it, many understand it.
* If you can learn a few phrases of Japanese, the locals will be surprised and appreciative.