sunomono vinegar is a type of Japanese vinegar that is often used in the preparation of sunomono, a type of pickled vegetable dish. it is made by adding sugar and salt to rice vinegar, and has a mild, slightly sweet flavour. sunomono vinegar is used to marinate vegetables before serving, giving them an ideal flavour and texture. it is also often used in the preparation of sauces and dressings. sunomono vinegar can also be used in other Japanese dishes to add flavour and aroma.