Japan is a vending machine powerhouse. Therefore, there are many casual restaurant that selling the food voucher. We buy it with a vending machine instead of ordering to a clerk. When we sit down and pass the ticket to the clerk, that dish will be carried. In short, it is prepayment.
However, an old-fashioned button-type ticket vending machine does not have English notation. Foreigners may not know which button should be pressed.
Recent ticket vending machines that have become full touch panels may switch the display language to English, Chinese, and so on.