That it came from Nobeoka is not in dispute. Everything after that is. The version in wide circulation says a western-style restaurant in the town had a staff meal of fried chicken soaked in sweet vinegar, and that two cooks carried it out into shops of their own. It is a tidy story and it is repeated almost everywhere.

The shop at the center of it, Ogura, states plainly on its own site that nobody there ever worked at that restaurant. Their account names the founder's elder brother, described as a restless man always trying to invent something, who was turning over the problem of chicken breast: cheap, lean, dull, and hard to make anyone want.

His solution came from watching children eat. They were dunking fried chicken into the sweet vinegar left over from pickled horse mackerel, the nanbanzuke. He built the dish around that. The tartar sauce, by this telling, came from a separate observation about dried squid being eaten with mayonnaise. It was on the menu before 1964.

Two origin stories, one town, and a shop contradicting the popular one in public. I am not going to settle it here. Both are worth knowing, and the disagreement itself tells you how much the dish matters to the people arguing.