From Ito down through the whole Izu peninsula, this was food eaten standing on a boat. Horse mackerel comes out of the net, gets chopped fine with ginger and scallion, goes onto rice, and hot tea or dashi is poured over the top. Soy sauce and wasabi adjust it. Total elapsed time, if you are not fussy, is about as long as it takes to describe.

Where the name comes from is unsettled. One account says it is from magomago suru na, stop dithering and eat, which is what you say to a man holding a bowl when there is a net to haul. Another says the dish was so good you would want to feed it to your grandchildren. A third claims it is a worn-down pronunciation of maguro chazuke.

Nobody has resolved this and I doubt anybody will. What interests me is that all three explanations agree on the circumstance even while disagreeing about the words. Whatever the name means, it was said quickly, on a moving deck, to someone who needed to finish eating.

The hot liquid does something else worth noting. It takes the raw edge off the fish, which is why this is the dish that children who dislike sashimi will accept. Fishermen's food, invented for speed, turns out to double as the gentlest way into a bowl of raw mackerel.