Research places on your itinerary on the Internet. You’ll find a plethora of useful information about major tourist sites, restaurants, and things to do and see. There are also YouTube videos showing you how to buy train and subway tickets and how to use vending machines. Use hyperdia.com to look up schedules and compare rates. Print out hotel names and addresses in Japanese in case you need to ask a native speaker for directions.
A Japan Rail Pass is useful and economical if you plan to travel long distances while in Japan. Purchase your Japan Rail exchange voucher prior to departure as you must purchase it outside of Japan. You can choose 7-, 14-, or 21-day passes that are ordinary (coach) or green (superior class). After arriving in Japan, you need to go to the JR travel office located in airports and major train stations to exchange the voucher for the pass. The clerk will give you a validated pass with the date you have chosen as your start date, which does not have to be the date of arrival.
Avoid boarding trains at rush hour. The speaker at an East Asian studies seminar I attended said that if you open a newspaper and put it on the floor, he could demonstrate that four people could stand on it, but during rush hour in East Asian countries, the number of people would be seven. You may have seen video clips of professional people pushers with their gloved hands pushing more people into the train. This is where the rules of etiquette are abandoned by some men who grope women and petty criminals who pick your pocket or purse. Many trains have separate cars for women available during rush hour.
You might consider packing slip-on shoes when going to Japan. When visiting shrines and private homes, you’ll be expected to take off your shoes and change into slippers that are provided. In a home, the washroom is considered an unclean area, so you need to exchange your slippers for the other slippers that are provided in the bathroom.
Don’t forget to carry a handkerchief in your pocket or purse as most public restrooms do not have paper towels. When my friend learned that I was going to Japan, she gave me about six handkerchiefs and I have since received several as gifts. It is considered an essential accessory.
ATMs are available at airports, train stations, post offices, and convenience stores but be aware that many are not operational 24/7. Most travel articles recommend that you convert some money to yen before travelling to Japan in case you need to purchase small items or a meal and the vendor does not accept credit cards.
Do not overdo the research; leave some things to spontaneity and serendipity, and interacting with the wonderful people of Japan!