It began as staff food in a Miyazaki izakaya. A triangular rice ball, wrapped in thin pork, grilled. Nothing more than that. The owner made them for the kitchen, then started handing them to regulars, and the regulars kept asking. In 1997 a shop opened selling them under the name nikumaki onigiri, and the thing acquired an identity.

The shape changed along the way. A triangle is awkward to wrap and more awkward to eat one-handed, so the rice balls gradually flattened into the barrel form, tawara-gata, which is now what everyone means by the name. Small design decisions like that tend to disappear from the story, and this one survived only because the people involved were still around to mention it.

The pork is cut, then left overnight in a soy-based tare before it goes anywhere near rice. Grilling drives that sauce inward. What you get is a dark, sticky outer layer and plain rice underneath, so the flavor is concentrated exactly where your mouth meets it and nowhere else.

At night the stalls appear in the entertainment districts of Miyazaki city. Some people eat one on the walk home, the last thing after drinking. Others buy a bag to carry back to a house where everyone is asleep.