I was just confirming the changes to the various ETC discounts (basically, after June weekend discounts are 30% off rather than 50% off, commuter discounts are now limited to mileage plan members and also contingent on using the commuter time periods numerous times a month, late night discounts now only 30% off, daytime shorthaul discounts have disappeared. The "before photo.") when I came across a real WTF discount scheme.
Hokkaido Expressway Pass
Reading the original Japanese, the requirements had my heart leaping for joy ー foreign passport holder or Japanese passport holder with permanent residence outside of Japan ー only to be dashed almost immediately with "must also hold an international driving permit for driving in Japan." It is also limited to cars from a list of seven rental firms. You receive the ETC card from the rental company.
The English regulations make no mention of the international drivers permit, so I don't know whether that crept in to the Japanese by someone officious saying "of course these people need a permit to drive in Japan" but it is not a formal requirement, or what. Seeing as it is the car rental companies which handle the paperwork and hand you the card I will guess that they will not refuse you if you have a Japanese drivers licence, but my guess has as much value as yours.