Onigiri or musubi, are the Japanese answer to the sandwich. These balls of unseasoned rice have aristocratic beginnings, much like the sandwich, and similarly have evolved into a casual and convenient food that anyone can make at home.
Often wrapped in nori, just like sushi, the difference here is the focus on the rice, rather than the fish. While sushi is not typically prepared at home, onigiri is an everyday food. They are prepared by mothers for lunch boxes, are available in corner stores, and are the perfect sustenance to take along on hikes, picnics, train rides, and road trips.