Are you asking what to do if you can’t buy the Shinkansen with a credit card? Check whether it is a UnionPay card. According to a query on the iAsk Knowledge Network, credit cards can be used at Shinkansen windows and ticket machines, but UnionPay cards cannot be used. The Shinkansen is Japan's high-speed railway. The first line was opened to traffic on October 1, 1964. It is the first high-speed railway in the world to be put into commercial operation.