Mirin is a rice wine widely used in Japanese sauces and marinades including tempura- and noodle dipping sauces and teriyaki sauce. It's naturally sweeter and lower in alcohol than sake. Hon Mirin (“true” mirin) has around 14% alcohol and no salt and therefore has to be sold and taxed like wine and is consequently hard to find. Other mirin varieties either have salt added or alcohol withdrawn in order to avoid being regulated as an alcoholic beverage. Mirin quality varies greatly and, as with so many things, it pays to read the label. Avoid "aji mirin", which is a mirin imitation that is artificially sweetened with glucose syrup and corn syrup. I order Mitoku Organic Mikawa Mirin from naturalimport.com.