On an island of carpenters, the houses are built alike. Kasashima is a settlement on Shiwaku Honjima in the Inland Sea, latticed townhouses along lanes narrow enough that the whole village can be walked from the harbour without needing to plan a route. Ship's carpenters lived here, and they are said to have taken work off the island as well, building houses and temples on the mainland and returning between commissions.

Kasashima was designated an Important Preservation District in April 1985, and the lanes remain too narrow for two cars to pass, which is one reason they have kept their proportions. The boat from Marugame takes about thirty-five minutes. The population is in the two hundreds, and seeing a doctor means crossing to the mainland — the standing arithmetic of island life, which shapes the age profile more than anything else does. The similarity from house to house, in how the lattice is divided and how the eaves are finished, is generally attributed to the same body of craftsmen building one after another.

On an island of carpenters, your own house is the sample. To win work elsewhere you have to show what you can do, and here the village itself functioned as the portfolio, standing where any visiting client would see it on the way up from the boat. Under those conditions a consistent manner of building is not a mystery. The skills went out from this island for generations, carried in the heads of men who worked all over the region. The place where they are still most densely visible is the island they left from, in the ordinary houses nobody was paid to build.