The prices on the menu were different for Japanese people and foreigners. Why?

It is possible that the prices listed on the menu for Japanese people were in yen, while to make the amount easier to understand for foreigners, the menu listed a price in U.S. dollars or Chinese yuan, for example. Or, as a form of hospitality the restaurant created a menu of items popular among foreign visitors and therefore had a separate menu in a foreign language. You can also order from the Japanese menu, so check with the restaurant staff.