Pork large intestine, not split open, cut across into rings while still a tube. Almost everywhere else the intestine is opened and cleaned flat before it reaches a grill, so this shape is unusual. Atsugi is pig country and has been for a long time, and cutting it this way has been the local habit for generations.

The fat stays on the inside of the tube. On the grill the rings contract and roll into little barrels, which is what the name describes: shiro for the cut, koro for what it does over the fire. The outside browns and crisps, the inside stays springy and yielding, and the fat inside melts sweet rather than heavy.

It is not parboiled. The intestine is distributed raw and reaches the restaurant the same day the animal is processed, which is the entire reason the dish can be cooked this way at all. Freshness here is a structural requirement, not a boast.

Each shop mixes its own sauce and nearly all of them are miso-based. In 2008 a group of local shopkeepers took it to the national B-grade gourmet competition and won, and the name traveled out of Atsugi. That group disbanded in 2019, twelve years after it formed, having done what it set out to do.