There is nothing inside. Four plain steamed buns, made without filling, are threaded onto a bamboo skewer, painted with a sweet-salty miso glaze and held over charcoal until the surface chars and the glaze bubbles. The skewer itself gets hot, and there is nothing to be done about that except hold it anyway.

The ancestor is said to be the unfilled sake-leavened bun that farming households in the province made at home for themselves. A shop in Maebashi began selling them glazed with miso in 1857, and that is the version usually cited as the start. It has been going for more than a century and a half and the shape has not altered.

At first the glaze was miso alone, because sugar was expensive. When black sugar syrup became widely available in the Meiji years, the sauce turned into the sweet-and-salty one now used. The sweetness arrived late.

Gunma lived on silkworms and on weaving, and the thing is said to have spread through the province among the merchants and manufacturers of that trade. It appears at the first market of the year, at cherry blossom time and at every summer festival, and it is almost always sold outdoors, from a stall, to people who are standing up.