The noodles are made using a length of green bamboo. The maker sits or stands on one end of the pole and bounces on it, using their own body weight to press the dough outward, working back and forth across it repeatedly.

What that produces is uneven. The noodles come out crimped and irregular, no two quite alike, which no machine would tolerate. Because the dough traps air pockets during the process, heat moves through the noodles quickly, they cook in a short time, and they finish with a strong chew.

The origin given for it is the Taisho period, when a Chinese cook working in the town is said to have taught the technique to the people around him, who then taught it onward. The soup is a clear, light soy sauce broth made with local water, deliberately kept out of the way of the noodles.

There are more than a hundred and fifty ramen shops in Sano, some of them over a century old. One explanation offered for why the bamboo survived is not romantic at all: most of these are small family operations, and a proper noodle machine was expensive. A piece of equipment that nobody in town could afford to buy turned, over a century, into the thing the town is now known for.