The name means hand-mixed, and that is the whole method. Bonito is sliced, steeped in a soy-based marinade, and then worked into vinegared rice with the hands rather than laid on top of it. Nothing is arranged. The fish disappears into the rice and comes back up in pieces.

It is said to have started with fishermen at Wagu on the Shima peninsula, some time in the Edo period, eaten out on the boat. The likelier sequence runs the other way round. It appears to have been a celebration dish that a boat owner laid on for his crew when the catch was good, and it moved onto the deck later, as the pattern of the bonito fishery changed.

Any red-fleshed fish will do — bonito, tuna. Because the slices have been sitting in the marinade they do not water down the rice when they are mixed through it. Shiso, ginger and shredded nori go over the top of it.

It only became known outside the peninsula in the 1960s, when somebody picked it up as a thing to put in front of visitors. There is a long gap between a meal eaten standing on a deck and the same meal arriving in a lacquered bowl. Most local specialities have that gap somewhere in them; this one has never bothered to hide it.