A black-plastered storehouse for the family's goods

To the southwest of the main house at the Iwase residence in Koyamazaki, on the eastern side of Tsuchiura in Ibaraki Prefecture, stands a dark, solid storehouse built to hold the family's household goods. The Iwase family served as nanushi, the village headman, of Koyamazaki through the Edo period (1603-1868), and the estate storehouse (yashikigura) is the store that kept their furniture, utensils and valuables rather than their crops.

The building is a true earthen-walled storehouse (dozō), two storeys tall, set on a north-south line. It measures 6.4 metres along the front and 4.2 metres in depth. Its roof is a gabled pantile oki-yane, a separate roof set over the earthen shell, with eaves carried across the whole eastern face. The thick outer walls are finished in black plaster (kuro-shikkui); inside, the plaster is white and the horizontal tie-beams (nuki) are left exposed. Storage compartments are built against the walls. The scale and finish were chosen, in the words of the official record, to suit the large main house it serves.

The estate storehouse dates to the late Edo period, placing it among the earliest surviving parts of the compound and a generation or more before the Meiji miso store and the Showa east gate.

Why the storehouse was registered

On 28 April 2010 the estate storehouse was entered on the national register of tangible cultural properties (tōroku yūkei bunkazai), in the 67th round, under reference number 08-0233. The register, established in 1996, protects buildings roughly fifty years old or more that contribute to the historic landscape, under a framework lighter than designation as an Important Cultural Property. It is meant to keep such buildings standing and in use rather than to fix them as untouchable monuments.

The storehouse was registered as part of the group of the main house and seven other structures. Among the storehouses on the grounds it is the one tied most directly to the household itself: where the rice and miso stores held the produce of the land, this dozō held the goods of the family. Its registration helps keep the social and domestic side of a headman's estate legible, alongside the storehouses of its working economy.

What rewards a closer look

The first thing to read is the black plaster. A dozō finished in kuro-shikkui is heavier and more emphatic than a white-walled store, and the choice signals that this building was meant to match the dignity of the main house standing just to its northeast. Set against the white-plastered miso store on the same grounds, the contrast shows how the family used colour and finish to distinguish one storehouse from another.

Inside, the construction is laid bare in a way the exterior hides. The walls are white, and the timber tie-beams that brace the thick earthen shell are left visible, so the structure that makes a dozō fireproof and strong is on plain view. Built-in compartments line the walls, the practical fittings of a working store. The placed roof, raised as a separate shell above the earthen box, is the standard technique that lets a dozō shed rain without trapping damp against its walls.

The Iwase residence is a private home and is not open to the public, and the storehouse sits well inside the grounds, so it cannot be seen from the road. Visitors who want to study this kind of earthen-walled dozō at close range can do so at open-air architectural museums and preserved merchant and farmhouse estates across the Kanto region, where black- and white-plastered storehouses are kept open.

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Q&A

QWhat did the estate storehouse hold?
AIt stored the family's household goods, such as furniture, utensils and valuables, rather than crops. The rice and miso stores held the produce of the land.
QWhy are the walls black?
AThe outer walls are finished in black plaster (kuro-shikkui), a heavier, more formal finish chosen to suit the large main house the storehouse stands beside.
QWhat is a dozō?
AA dozō is a storehouse with thick earthen walls plastered over a timber frame, a traditional fireproof store. Here the interior is white-plastered with the tie-beams left exposed.
QWhen was it built?
AIt dates to the late Edo period, making it one of the oldest surviving parts of the compound, earlier than the Meiji miso store and the Showa east gate.
QCan I visit the storehouse?
ANo. It stands within the private grounds and is not open to the public or visible from the road. Comparable dozō can be seen at open-air museums and preserved estates elsewhere in the region.

Basic Information

NameIwase Family Residence Estate Storehouse (Iwase-ke Jūtaku Yashikigura)
LocationKoyamazaki, Tsuchiura City, Ibaraki Prefecture
DesignationRegistered Tangible Cultural Property (building); registration no. 08-0233
Registered28 April 2010 (67th round of registrations)
Count1 structure
StructureTwo-storey earthen-walled storehouse (dozō), pantile roof; building area about 39 m²
PeriodLate Edo period
OwnerPrivately owned
Public accessNot open to the public; within the private grounds

References

National Database of Cultural Properties, Agency for Cultural Affairs (Iwase Family Residence Estate Storehouse)
https://kunishitei.bunka.go.jp/bsys/maindetails/101/00008088
Ibaraki Prefectural Board of Education, Cultural Properties (Iwase Family Residence, main house and seven other structures)
https://kyoiku.pref.ibaraki.jp/bunkazai/bunkazai-registered-6043/

Last verified: 2026.06.25