It is also called tonosama-zushi, lordly sushi, from an account in which it was presented to Kikkawa, the lord of the Iwakuni domain, in the Edo period, and pleased him.

The stated design problem was transport. Iwakuni castle stood up on a hill, and what was wanted was food that could be carried up there conveniently and in quantity.

The method is layered. The base of a wooden frame is lined with chisha leaves, seasoned rice is packed in on top of them, and then the surface is arranged with pickled Iwakuni lotus root, simmered conger eel, shredded omelet, and denbu. More chisha leaves go over that, and the next layer starts on top. Three to five layers in all, and the contents are as lavish as a castle town's produce allowed them to be.

For a large one, the craftsmen would stand on the pressing lid to compact it, which gives some sense of the scale involved. Cut it and you can see the layers in the face of the slice, the colors stacked in bands. It has been a dish for celebrations since the domain period, made in quantity for a great many people at once. A solution to the problem of getting food up a hill turned into the shape that a celebration takes.