Shortly after the war, when beef cutlets were still an unusual thing for anyone to encounter, a restaurant in Kakogawa worked out a version of western food that could be eaten comfortably with chopsticks, without anyone needing a knife and fork at all.

The construction is this: rice on a western-style plate, a flattened beef cutlet laid over the top of it, demi-glace poured across the whole thing, and boiled cabbage sitting alongside. The plate is western. The cutlery is not.

It has diversified considerably since those first years. Some versions use pork, chicken, or shrimp instead of beef, and sauces other than demi-glace turn up. More than a hundred restaurants in the city serve it, it appears in school lunches and university canteens, and supermarkets sell a bottled sauce for making it at home.

What holds all of that together is one decision taken at the start. The dish was designed backward from a single constraint, which is that the person eating it will be holding chopsticks. Everything else about it, the flat plate, the flattened cutlet, the rice underneath rather than beside, follows on directly from that single requirement and nothing else.