There is a small structure on the roof, for letting smoke out. Kaga Higashitani is a mountain district divided into four settlements, and the houses along the valley have red-tiled roofs with a raised smoke vent set on top. The vent releases the smoke from the open hearth below, and in passing through the roof space that smoke did useful secondary work: drying the thatch and the timbers, and keeping insects out of both.

This valley lived by charcoal. Trees were cut on the slopes, burned into charcoal, and carried down to be sold in the settlements below, and that cycle was the main business here for generations. Kaga Higashitani was designated an Important Preservation District in November 2011. Across the four settlements there are a few dozen households, and the population is ageing. Kaga-Onsen station is about thirty minutes away by car, and the depopulation has worked its way down the valley, emptying the furthest settlements first.

Charcoal burning requires both a mountain and a market. You had to live within reach of the trees you were cutting and within reach of the people who would buy the result, which is why every one of these settlements sits at an awkward middle height — too high to be convenient, too low to be in the forest proper. That position was a precise answer to a specific economy. When the country changed what it burned, the meaning of that position was the first thing to disappear, well before the houses did — and there is no second use for a settlement sited halfway up a slope for reasons that no longer apply.