The noodles are cut by hand, using the technique of soba making rather than of ramen making, and what that produces is a broad, high-hydration noodle with a pronounced crimp that holds soup along its length. The soup is a clear soy-based broth drawn from pork bone and chicken frame. Many shops still use the old-fashioned chashu with its edge painted red with food coloring.

The line is usually traced to 1921, when a man who had trained in Yokohama opened a hand-cut noodle shop here called Kamegen.

What produced the present situation was one person. Takei Toraji opened his shop in 1969, and when people came asking to be taught, he taught them, without holding anything back.

Those apprentices set up on their own. People who trained under them set up in turn. That chain continued for decades, and there are now well over a hundred shops in a city of this size, which is why the ramen of Shirakawa is a category rather than a restaurant. It is worth being clear about the cause. No committee, no campaign, no branding exercise. One cook declined to keep his method to himself, and the number of shops in the town is what came of that decision, several decades later.