Anyone bothering to travel halfway around the world should try to pick up some language skills. It's easy and fun. Buy a pocket translation book (Lonely Planet, Berlitz, etc.) and look at it on the plane ride over. Look up hello, thank you, please. where is the bathroom, simple handy phrases you know you will be able to use. Write down the the phrases in one handy place (like the inside front or back cover). Writing them down will help you learn them.
Whenever you leave your hotel, take the hotel's business card with you with the address in japanese. that way, you can always show it to someone, like a cabdriver and get back to your hotel.