Hyakunensha Main Building

The Main House of Hyakunen-ya: A Meiji Residence That Was Moved and Rebuilt

Two dates share the registry entry for this building. It was raised in 1890, the twenty-third year of the Meiji era. Then, around 1917, it was taken apart and reassembled on the plot it occupies today in Tosayamada, a former post town at the foot of the mountains in eastern Kochi Prefecture.

Relocating a timber house was ordinary practice in Japan. Joinery held the frame together without nails at the critical points, so a building could be numbered, dismantled, carted, and raised again. What makes the Hyakunen-ya main house unusual is the scale of what was moved.

The plan runs seven and a half ken along the ridge by five and a half ken in depth, roughly 13.6 by 10 metres, with a footprint recorded at 201 square metres. It is a single-storey building, and that horizontality is the point: rather than climbing, it spreads. The house sits close to the middle of a long north-south property, with a storehouse at the southeast corner, a small gate at the northeast, and concrete walls closing the western edge.

The name Hyakunen-ya translates roughly as "the hundred-year house." Local accounts connect the family line to a physician who served the Yamauchi lords of Tosa, though the building standing here dates from the Meiji era, three centuries after the first lord's time, and the tradition should be read as a story about the household rather than about these timbers.

Registered, Not Designated: What the 1996 System Changed

Japan protects cultural properties at several levels, and the distinctions carry real legal weight. A National Treasure (kokuho) or an Important Cultural Property (juyo bunkazai) is designated, which brings strict controls and substantial state involvement. A Registered Tangible Cultural Property (toroku yukei bunkazai) works differently.

The registration system arrived with a 1996 amendment to the Law for the Protection of Cultural Properties. The problem it addressed was arithmetic. Japan's Meiji, Taisho, and early Showa building stock was disappearing faster than designation could evaluate it, and designation was too heavy an instrument for a house someone still lived in. Registration asks only that the owner notify the authorities before altering or demolishing the building. In return come tax relief and technical guidance. Ownership remains ordinary ownership.

The main house was registered on 1 December 2003, in the thirty-ninth round of registrations, under number 39-0123. Public notice followed on 25 December. The criterion applied was contribution to the historical landscape of the nation, one of the three grounds available under the system.

Four other structures on the same property were registered on the same day: the storehouse, the gate, the inner wall, and the outer wall. The Agency for Cultural Affairs treated them as five separate entries rather than one, which is standard practice and which reveals how the assessors read the site. Each element was judged to stand on its own.

Reading the Roof

Anyone who stops in front of the house tends to look up, and the roof rewards that.

The main volume is hipped, with the ridge running east to west, and covered in sangawara pantiles, the interlocking clay tile that became the standard of the Edo period and after. Around the perimeter the roof steps down one level and continues at a lower pitch, a treatment the registry describes as resembling shikoro-buki. The word borrows from armour: shikoro are the overlapping lames that hang from a samurai helmet to guard the neck. The roof does the same thing in tile, layering downward in stages.

That step matters visually. Without it, a hipped roof over a footprint this wide would read as a single heavy mass. The break splits the slope into two registers, catches a line of shadow along the join, and lets the eaves come down closer to human height at the edges.

At the southeast corner a section of the building pushes outward, and here the roof changes character again, resolving into a gable rather than continuing the hip. Three roof geometries, then, on one house: hipped centre, stepped skirt, gabled projection.

The assessors called the overall effect commanding, and singled out its prominence in the surrounding streetscape. In a town of modest frontages, a 201-square-metre single-storey house with a roof worked to this degree is not competing with its neighbours so much as belonging to a different order of building.

Visiting: The House Is Now a Guesthouse

The property operates as Hyakunen-ya BASE, a whole-house rental that began accepting guests in May 2022. Booking the house means booking all of it, which is the closest thing to a genuine encounter with a registered building of this kind: not a roped-off route through preserved rooms, but a night with the sliding partitions open and the horigotatsu sunken hearth warm.

The site is about a two to three minute walk from JR Tosayamada Station on the Dosan Line, which puts it within easy reach of Kochi city, roughly thirty minutes by car. Reservations and current operating details go through the guesthouse directly.

For those not staying, the exterior reads well from the street. The gate at the northeast, the concrete walls along the west, the tiled roof rising behind them: the ensemble is legible from outside, and the registration was granted for exactly that contribution to the streetscape. Please respect the privacy of the property and any guests in residence.

Tosayamada repays a slow walk. The Kogi no Ido, a public well laid out in the early Edo period under the Tosa administrator Nonaka Kenzan, sits a few minutes away, and Matsuo Shuzo, a sake brewery founded in 1873, stands in the western half of the old town.