Onigiri (jp. お握りor 御握り), also known as omusubi (お結び) is a food of Japanese cuisine.
Onigiri is made from a white rice and formed into triangular or oval shapes (hence in English it is sometimes referred as "rice ball"). It is often wrapped in nori (seaweed) and contains filling of salty or sour variety, like eg. umeboshi, salted salmon, katsuobushi, or kombu.