A single length of bamboo is split down into the tines. A Takayama chasen is made by splitting the end of a bamboo tube, thinning each resulting strip, and then separating the inner and outer tines while shaping the whole. The number of tines is set by the school of tea it is made for — anything from a few dozen to over a hundred — and the splitting is done to that number from the beginning.

The households making them are gathered on the hills here rather than scattered, and the museum and the workshops show the sequence from the first split through to the finishing of the individual tines. Bamboo behaves differently according to how it was dried and stored, which changes how it splits, so managing the seasoning of the material is part of the craft rather than a preliminary to it. Kintetsu reaches Namba in about thirty minutes, the research park provides employment nearby, and housing estates spread across the surrounding hills.

A tool becomes more precisely specified the narrower its use is. A chasen exists for a single motion — whisking tea — and everything about it, the tine count, the curve, the stiffness of the individual tines, has been adjusted to that motion over a long period by people who were watching the result in the bowl very closely. Nothing else is asked of it. The narrowness of the purpose is exactly what allowed the form to be refined this far, over this many generations. A more versatile object could never have been taken to the same degree, because there would have been no single test to refine it against.