The JNTO is incredibly helpful and responsive to travelers. We contacted them at the very last minute to get rail passes — they were able to assist us immediately, directing us to a local affiliate who arranged for our rail passes. They also provided us with a huge package of travel information which arrived via post from Japan within a week. Contact them for maps, brochures, assistance in making reservations, rail passes, and to answer various questions. Contact them via telephone or email. If you contact the JNTO by e-mail, be sure to include your postal address. Link to the JNTO website is below; we recommend visiting the site as it provides useful information on a variety of topics as well as contact information for the various offices.
Once in Tokyo, you can visit the JNTO-operated Tourist Information Centers. The TIC are located in Terminal 2 of Narita or at 3-5-1 Marunouchi, 1st Basement Floor, Chiyoda-ku, 03-3201-3331 (located near Tokyo Station). Here you can acquire maps and assistance. Office hours are 9 a.m. – 5 p.m. weekdays and 9 a.m. – noon on Saturdays.
Other services for tourists include Japan Travel-Phone — a phone service that offers travel advice and information in English. The Tokyo number is 03-303-4400; outside of Tokyo, you can dial 0120-222-800 or 0088-222-800. There is a per minute charge (¥10).