Umeboshi Onigiri (Japanese Rice Balls with Pickled Plum)

Umeboshi onigiri is one of the most classic Japanese rice balls. Plain onigiri with salty, sour pickled plums tucked inside makes for a simple but delicious combination. Growing up in Japan, umeboshi was a standard onigiri filling I often saw in Bento lunch boxes, convenience stores, and homemade meals. The umeboshi adds a perfect little touch of flavor without being overpowering. I often make this simple recipe at home because it is easy, satisfying, and brings back the familiar taste of Japanese home cooking. What is Umeboshi Onigiri? Umeboshi onigiri is one of the most traditional types of Japanese rice balls made from plain steamed rice filled with pickled plum. Onigiri is made by shaping cooked short-grain rice by hand or with an onigiri mold, usually into a triangle or round shape. Umeboshi is made from Japanese ume fruit, which is often called a Japanese plum in English, but ume is different from Western plums. It has a distinctive salty, sour, and slightly fruity flavor that goes especially well with plain rice. The umeboshi can be placed in the center of the rice as a filling, mashed into umeboshi paste, or mixed through the rice for a more even flavor. The finished onigir...