The name comes from an old word for thunder. Hatahatagami, written with characters meaning the thunderclap deity. When the sea turns rough and thunder is rolling across it, this fish appears in enormous numbers close to shore, for a short window, to spawn. That coincidence gave it the name it carries.

In Akita it is said that you cannot see in the new year without hatahata. That is not a figure of speech about being fond of the fish. It is a statement about what the calendar requires of a household.

Hatahata-zushi is that fish preserved as a fermented sushi, packed down with cooked rice and a generous quantity of koji, which is what a rice-growing province would naturally reach for.

The method varies from district to district. Salting the fish immediately after it is landed is described as the older way of doing it. It goes into brine for around three days, and then rice and koji are layered in with it and the whole thing is weighted down and left alone. What comes out is cut up and served at new year, and opening the tub releases the sourness all at once. A fish that arrives with the thunder, put away using the technique of a place that grows rice. Two things this prefecture is defined by, meeting inside one wooden tub.