Zōsui is a Japanese rice soup characterized by its thin consistency. It is made with rice, water, and additional ingredients such as meat or vegetables. The soup is commonly flavored with soy sauce or miso. Zōsui is believed to be an ideal soup for curing colds, so it is mostly served during winter.

In the past, it provided a great way to use all of the unwanted ingredients, so the cooks started reusing cold rice by combining it with miso soup, and the healthy zōsui soup was born. Today, cooks often use the stock left from Nabe hotpot, because when all the meat and vegetables are gone, what is left is a flavorful broth that pairs ideally with rice for the creation of a new zōsui dish.