Moist, chewy, and hearty, onigiri or omusubi are Japanese rice balls and a favorite picnic food since the 11th century, when they were known as tonjiki and recorded as such in the diary of Lady Murasaki, author of The Tale of Genji (which is believed to be the world's first novel!).

However, the origins of the dish are much earlier than the time of Lady Murasaki. In the Nara period, before chopsticks became popular, rice used to be rolled into small balls in order to be easily picked up and consumed. Typically, onigiri is wrapped in nori seaweed, but that practice did not come about until the late 16th century.

The stuffings might include salmon, umeboshi plums, grilled or pickled mushrooms, or various vegetables. Today, onigiri is often made at home and sold everywhere throughout Japan, from parks and beaches to convenience stores or upscale grocery stores.