You really don't need to speak much of the local language to get food in a restaurant. I have no experience of Japan but I've spent close to a year in China spread over a dozen trips. I ate in a number of different places, bought silk for my wife, etc., all without being able to speak the local language. My experience is that throwing yourself on the mercy of the the waiter works quite well with some sign language and perhaps a simple phrasebook not just in China but also in Spain. After all the restaurant wants you to come back and to tell your friends how good it is.