Okamoto Family Residence Main House

A Main House Dated by Its Own Ridge Tag

The Okamoto Family Residence Main House (岡本家住宅主屋, Okamoto-ke Jūtaku Shuoku) is a two-storey timber house at Mori in Ozu Town, Kikuchi District, Kumamoto Prefecture, built in 1840 and listed as a Registered Tangible Cultural Property on 23 August 1999. It is the anchor of the ten registered structures on the Okamoto property and carries registration number 43-0026.

The house has a building area of 349 square metres under a tiled roof. Its date is not family lore. A Munafuda, the wooden ridge tag carpenters fixed in the roof at completion, records the construction of the main body, and that single piece of evidence turns out to matter a great deal in why the house was registered.

The Agency for Cultural Affairs singles out two features of the exterior. One is the double roof, a lower roof tucked beneath the main one so that the house presents a deeper, more layered profile to the approach. The other is the Namako-kabe at the base of the walls: flat tiles fixed to the plaster with their joints raised in white lime, a finish that sheds rain and resists fire and, not incidentally, looks the part for a household of samurai rank.

A Floor Plan That Bends the Rules

Ozu Town's description explains the plan. The Okamoto Family Residence Main House is U-shaped, open to the north. Two parallel wings run along the north side, the formal reception rooms to the west and the private rooms to the east, and each is exactly three Ken deep. That dimension was not a free choice. Edo-period building rules limited the beam span of a dwelling to three ken, and the northern wings obey.

On the south side, though, a single large roof sweeps across the whole plan. The town reads that as the three-ken rule quietly giving way, and as a sign of a rural family gaining strength while the shogunate's order was beginning to loosen. One building, in other words, holds both the rule and the moment it stopped being followed.

The farmhouse is still there too. The earth-floored work area and kitchen keep an older agricultural layout, so the reception rooms where a samurai household received guests sit under the same roof as the spaces that ran the farm.

Why It Was Registered, and Where the Sources Disagree

The main house was registered under the criterion for buildings that would be difficult to reproduce. The Agency notes Meiji-period additions and alterations but stresses that the date of the core structure is fixed by its ridge tag, and it calls the building a fine example of a country samurai house in northern Kumamoto.

Ozu Town tells it slightly differently, describing the Okamoto Family Residence Main House as essentially unaltered since construction. The national and municipal accounts do not agree on whether the house was altered in the Meiji period, and the published material does not say which parts were changed or when.

On size they match: the Agency gives a building area of 349 square metres, the town about 350 square metres for the main house.

Seeing the Main House

The house is lived in and the interior is not open. Because it stands near the centre of the plot behind the front gate, the view from the public road on the west side is partial, glimpsed past the gate and fences rather than seen whole.

Photograph only from the road, and do not step inside the gate or aim a lens into the living quarters. Standing square to the front gate is still worthwhile: the sequence of bridge, gate, wing walls and the house behind them gives a clear sense of how deep a samurai compound was meant to feel.