Frequently Asked Questions (FAQs)
JRailPass.com FAQ

Can I purchase a JR Pass if I have dual citizenship?

Citizens with dual citizenship are eligible for the Japan Rail Pass, as long as they use their non-Japanese passport to enter the country.

Those who enter Japan for tourist or leisure purposes will receive a Temporary visitor stamp or sticker at the passport control of any Japanese airport. If a traveler uses their Japanese passport, they will not receive a Temporary visitor stamp which is necessary to obtain a Japan Rail Pass.

Note:
If you enter Japan with a Japanese passport or for other purposes than tourism / leisure / sightseeing, you will not receive the Temporary visitor stamp / sticker. Should you attempt to exchange your order for a Japan Rail Pass without the stamp / sticker, you will not be able to make the exchange.