Along the Kiso, Nagara, and Ibi rivers, in the middle and western parts of Gifu, this rice soup belongs to summer. It began as a way of rescuing sweetfish that had been damaged during the catch. A bruised ayu was hard to sell whole, and grilling it plain and breaking it down into a pot solved that problem without wasting anything. Practicality first.

The fish is grilled unseasoned until the skin browns and the smell fills the kitchen, then the head and bones come out and the flesh is pulled apart. Cooked rice is rinsed in water first, to wash off the surface starch, so the finished bowl stays clear instead of turning to paste. Broth, rice, fish, a brief simmer. Scallion and a strip of yuzu peel go on at the end.

Knowing the origin changed how the first spoonful tasted, and not in the direction I expected. This is supposed to be the thrifty option, the thing you do with a fish nobody would buy. It arrives tasting like a small luxury. I sat there faintly confused about which version of the story to believe.

Both, probably. River fish were plentiful here and money was not, and a summer bowl that used up the imperfect ones was simply sensible. Now it closes the meal at the riverside yana restaurants, and a packaged version made with Nagara ayu and Gifu rice sells at roadside stations.