The houses stretch sideways, following the contour lines. Tonegawa is a settlement built by stacking stone up a steep slope and setting long, single-storey farmhouses of the Shiiba type on the terraces that result, so that the buildings run along the hillside rather than facing out from it. The reason for the proportions is simple: level ground won from a slope comes in narrow bands, and the plan of the house stretched out in a line to fit the band it was given.

With the rooms in a single row, the house can be walked straight from one end to the other, and everything that follows from that — how air moves through it, the order in which it is cleaned, where people sit in the evening — is decided along one direction only. Tonegawa was designated an Important Preservation District in December 1998, and a very large cedar stands among the houses, old enough to have been there before any of them. There are a few dozen households. The village centre is about thirty minutes away by car, Hyūga is two hours off, and the roads ice over in winter.

The shape of a mountain settlement is decided by how the ground is cut. Extending a level surface sideways requires less stone than extending it downhill does, so both the houses and the fields grew long rather than deep, and the whole village ended up lying parallel to the contours. Nobody drew that arrangement. Stand on the slope opposite and the line of the houses reads as a line of the landform itself, because in a fairly literal sense that is what it is. The village is a contour that somebody has built along.