Shirasu, also known as whitebait chirimen, are baby sardines (iwashi) that are less than 2 centimeters in length. The skeletons of immature fish is not yet well developed so they have a texture that is soft and tender. This kuji shirasu is from Ibaraki prefecture where they are processed at a factory near the pier. They are boiled and then lightly dried to preserve them: raw shirasu spoils extremely quickly and is rarely seen outside of coastal towns. These tiny fish are ready-to-eat and packed with mild, umami-rich flavor. Shirasu is most commonly used as a topping on other foods such as white rice, salad, pasta, and even pizza.