Sanshu onigawara ornamental tiles

The place behind Sanshu onigawara is western Mikawa, a roof-tile region in Aichi. The Yahagi River brought clay from Mt. Sanage downstream, creating a supply of clay suited to roof tiles, while the coast gave finished tiles a route by sea toward Edo.

Its regional character is concrete: Mt. Sanage clay, the lower Yahagi River, coastal transport, and tile workshops belonged to the same production setting. Takahama and Hekinan appear among the listed business locations, and the Sanshu tile cooperative is based in Takahama, giving the craft a visible maker community in Aichi.

After Tokugawa Yoshimune encouraged tiled roofing in 1720, Sanshu roof-tile production began to flourish more fully as a local industry. The date marks a turning point in demand and production rather than a single origin moment for every onigawara form.

Onigawara were placed on tiled roofs and linked with protection from misfortune, warding off harm, prosperity, and wealth. On a ridge or roof edge, the face and form were part of the building envelope, facing weather, streets, and household hopes for safety.

The form of Sanshu onigawara keeps the trace of handwork from the shaping stage. Makers may build entirely by hand using paper patterns, or rough-shape the piece with a plaster mold before finishing it by hand with wooden or metal spatulas.

Named steps such as paper pattern, base shaping, part shaping, and finishing turn a flat outline into a three-dimensional roof ornament or interior display object. The face, ridges, and edges come together through the pushing, trimming, and smoothing of wood and metal tools.

The silver-gray surface of Sanshu onigawara is not paint. The piece is left unglazed; after firing, oxygen is blocked while it remains at high temperature, and reduction smoking forms a carbon film on the surface, producing the color known as ibushi-gin.

That smoking process gives the tile a quiet metallic cast while preserving the fired-clay body beneath it. The color points back to a specific sequence: unglazed clay, heat, oxygen control, smoke, and carbon film.

Onigawara first belonged to the roofline, but Sanshu pieces later moved into daily interiors. Their uses expanded into tokonoma alcove ornaments and entrance displays, bringing the protective roof image into spaces where people could see it close at hand.

A tokonoma or entrance changes the viewing distance. On a roof, the ornament faces sky and street; indoors or near a doorway, the ibushi-gin surface, hand-finished lines, and roof-tile origins become details that can be read at eye level.

Sanshu onigawara is not only a past roof object. Businesses in Takahama and Hekinan remain visible in the production map, and recent makers have also worked on restoration connected with National Treasures and Important Cultural Properties.

The continuity rests in specific people and places: the Takahama-based cooperative, local workshops, hand-shaped roof-tile craft, and the forms and surfaces needed for architectural restoration. Sanshu onigawara therefore connects household entrances, tokonoma displays, and repair work on historic buildings.