The Japan Rail Pass is a multi-use discounted ticket, valid for travel on all JR national trains in Japan, including Shinkansen and Narita Express. Those who visit Japan from abroad under the entry status of “Temporary Visitor” can purchase this ticket.
It used to be sold only outside of Japan. However, it has been decided it will be available on a trial basis from the 8th to 31st March 2018. You will be able to purchase it at stations, including Sapporo, Tokyo, Osaka, Narita Airport and so on.