Kamaya-date: A Farmhouse Split in Two
The Mochizuki Family Residence (望月家住宅, Mochizuki-ke Jutaku) at 7 Takanawate, Kuroda, Shinshiro City, Aichi Prefecture, dates from the later eighteenth century and was designated an Important Cultural Property on 5 February 1974. The designation number is 01917 and the quantity is two buildings: the omoya, where the family lived, and the kamaya, which took the fire and the work.
What sets the main house apart is what it does not hold. No cooking range, no earth floor, no stable, no bath. All of that sits in the second building, roughly one ken away, about 1.8 metres, with its ridge set at right angles to the first. Carpenters along the Toyokawa called this arrangement kamaya-date; architectural historians class it as a split-building farmhouse. The result was that the living quarters never blackened. Smoke, the smell of animals, the damp work of hulling rice, all of it stayed next door.
The Mochizuki are said to descend from a retainer of the Takeda who, after the defeat at Nagashino in 1575, did not return to Mochizuki in Shinano but settled here instead. The first of the line was called Shirozaemon, and later generations took the name in turn. Gravestones and memorial tablets kept by the family run back to 1713, showing that life on this site predates the buildings by decades.
Not Age, but Completeness of Type
The Agency for Cultural Affairs places the house among the split-building farmhouses found from western Shizuoka into eastern Aichi, then adds a frank qualification: this house is not especially old, but it retains its former appearance well.
That sentence is the point of the designation. What is valued is not age but completeness of type. Kamaya-date farmhouses once stood in numbers from the Toyokawa basin to the Tenryu, and most were altered or demolished during the twentieth century. The Mochizuki house came down with its two-building arrangement intact and is regarded as the oldest surviving example of its kind, a reference point for reading the others.
Dating rests on inference rather than documents. Family tradition puts construction around 1689, but no ridge tablet, ink inscription or paper record supports it. The Agency for Cultural Affairs reads the structure as later eighteenth century for the main house and end of the eighteenth century for the kamaya, suggesting the working building went up, or was rebuilt, somewhat later. Shinshiro City, comparing scale, plan and column spacing against other farmhouses, estimates roughly three hundred years. Both figures appear on site, and the spread is best read as an honest admission of thin evidence.
The Main House: Four Rooms in a Grid
The main house runs 8.1 metres by 7.2, hipped and thatched, entered on the long eaves side. Inside is the regular four-room plan, four spaces of nearly equal size in two rows of two. The layout maps onto the character for rice field, so it is also called the ta-no-ji plan.
Each room carries a local name. The oe was the everyday living room. The okatte handled food carried in from next door. The odei served as both Buddhist altar room and guest room. The oheya was for sleeping. Together they come to a little over thirty-five square metres, small for a designated farmhouse, and the figure states plainly how large a farm this was.
The partitions repay attention. They are not fixed walls but board doors and paper screens, and they could be removed. For funerals, weddings, village meetings or the silkworm season, the divisions came out and the whole floor became a single room. A four-room farmhouse spent much of its life not divided into four rooms at all.
The roof structure is plain. The ridge piece is short and the ridge itself narrow. Houses of this type commonly carry three to five kurabone, and because corner rafters alone support the ridge piece, no ridge post is needed. Almost every surviving example does without one.
The Kamaya, and the Gutter Between
The kamaya measures 8.1 metres by 5.4, hipped and thatched, entered at the gable end, with pent roofs on the south, east and north. Everything the living quarters refused is gathered here: the range and the fire, the earth-floored working area for hulling and threshing, the bath, the stable. Thatch and firewood for the next rethatching were stacked in the space beneath the roof. About thirty-three square metres, and all of it a place of work. The entrance is on this side too, so anyone visiting the house came in past the fire rather than through the rooms.
Almost none of it is floored. Most is packed earth, and that single fact settled how the building was used. Water could be spilled, straw beaten, a horse led in. Along the length of the building, wet work was separated from dry: the cooking area with its range, the open working floor, then the stable. The bath and sink sit at the junction of the two buildings, projecting front and back, a few steps from both the fire and the rooms yet belonging fully to neither.
The structural description in the national database ends with a phrase worth noticing: including the junction between the main house and the kamaya. The place where the two buildings meet is treated not as an incidental fitting but as part of what is designated.
That phrase is there because the junction is the hardest thing about this form. The two ridges cross at right angles about 1.8 metres apart, so from the front the roofs draw a T. The eaves nearly touch, and rain falling into that narrow valley has nowhere to go. The answer was a gutter: a cedar log split lengthwise, hollowed out, lined with copper sheet and carried between the two roofs to drain into the forecourt. The log runs over eight metres. Everything else in the house rests on that gutter working. Let it fail and both buildings rot from the joint.
Why the Two Count as One, and Visiting Today
The main house alone is a small four-room dwelling with no range and no earth floor. The kamaya alone is a work shed that is almost all earth floor. Neither explains itself. The substance of this property is the arrangement: domestic functions divided between two buildings, linked by a gap of one ken and a single hollowed log. The designation reaches into the junction because that is what makes two buildings one item.
Step outside and set the two roofs side by side. The main ridge always stands higher than the kamaya's. Locally the reason is given as both propriety and luck, since the crossing shapes resemble a mallet of fortune. From the same T-shape comes another name for the form, shumoku-zukuri. The main house is entered on the eaves side, the kamaya at the gable end, and it is the meeting of those two approaches that produces the T.
Between 2018 and 2019, Shinshiro City rethatched both roofs and carried out seismic strengthening, a fifteen-month programme completed on 25 August 2019. The gutter was the central problem. Survey found the hollowed cedar log decaying, so it was replaced and a safety wire added. Strengthening was limited to three places across the two buildings, with plywood inserted inside existing walls. The frames were not taken apart.
Public opening is suspended for the time being, and Shinshiro City keeps that notice on its cultural property page. Some tourist listings still show the earlier terms, weekends and public holidays from 9:00 a.m. to 5:30 p.m. at 300 yen for adults and 150 yen for high school students and younger, but these no longer apply. Anyone planning a visit should contact the city's history and culture division in advance; permission for photography rests with the same office and is not published.
The relationship of the two thatched roofs reads clearly even from outside the boundary. Farmland opens around the site, and the Toyokawa runs a little to the south. Access is straightforward: from Shinshiro Station on the JR Iida Line take the Toyotetsu bus on the Tomioka route, get off at Kuroda and walk about fifteen minutes. By car it is about twenty minutes from the Shinshiro interchange of the Shin-Tomei Expressway.
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Q&A
- What is the kamaya-date form at the Mochizuki Family Residence?
- An arrangement in which the living quarters and the cooking and working building stand as separate structures. The two sit about 1.8 metres apart with their ridges at right angles. The form is found from the Toyokawa basin to the Tenryu and is classed as a split-building farmhouse, which is why the main house has no range, no earth floor, no stable and no bath.
- Why was the Mochizuki Family Residence designated?
- For completeness of type rather than age. The Agency for Cultural Affairs states plainly that the house is not especially old but retains its former appearance well. Most kamaya-date farmhouses were altered or demolished in the twentieth century; this one survives with both buildings intact and is regarded as the oldest of its kind.
- Why does the designation include the junction between the two buildings?
- Because it is the hardest part of the form. The eaves nearly touch and rain in the narrow valley has nowhere to drain. A cedar log over eight metres long, split, hollowed and lined with copper, carries the water to the forecourt. If that gutter fails, both buildings rot from the joint.
- When was the Mochizuki Family Residence built?
- No ridge tablet, inscription or document survives, so the date rests on inference. The Agency for Cultural Affairs reads the main house as later eighteenth century and the kamaya as end of the eighteenth. Family tradition says about 1689 and Shinshiro City estimates roughly three hundred years. The spread reflects thin evidence, stated honestly.
- Can the Mochizuki Family Residence be visited?
- Public opening is suspended for the time being. Tourist listings still showing weekend hours and a 300 yen adult charge are out of date. Contact Shinshiro City's history and culture division before travelling. The relationship between the two thatched roofs can be seen from outside the boundary.
Basic Information
| Name | Mochizuki Family Residence (望月家住宅, Kuroda, Shinshiro City, Aichi) |
|---|---|
| Location | 7 Takanawate, Kuroda, Shinshiro City, Aichi Prefecture |
| Designation | Important Cultural Property (structure), designation no. 01917, category pre-modern folk dwelling |
| Year Designated | 5 February 1974 (Showa 49) |
| Quantity | 2 buildings (main house 1, kamaya 1) |
| Dimensions | Main house: 8.1 m by 7.2 m, hipped thatched roof, entered on the eaves side (later 18th century). Kamaya: 8.1 m by 5.4 m, hipped thatched roof, entered at the gable end, pent roofs south, east and north, including the junction with the main house (end of the 18th century) |
| Owner | Privately owned; no owner name recorded in the national database |
| Public Access | Public opening suspended for the time being (Shinshiro City). Exterior viewing only; contact the city's history and culture division before visiting |
References
- Agency for Cultural Affairs, National Cultural Properties Database: Mochizuki Family Residence (main house)
- https://kunishitei.bunka.go.jp/heritage/detail/102/1264
- Agency for Cultural Affairs, National Cultural Properties Database: Mochizuki Family Residence (kamaya)
- https://kunishitei.bunka.go.jp/heritage/detail/102/1265
- Cultural Heritage Online: Mochizuki Family Residence, main house
- https://bunka.nii.ac.jp/heritages/detail/189103
- Cultural Heritage Online: Mochizuki Family Residence, kamaya
- https://bunka.nii.ac.jp/heritages/detail/122074
- Shinshiro City: Mochizuki Family Residence, Important Cultural Property
- https://www.city.shinshiro.lg.jp/kanko/minzokugeino/mochidukike.html
- Aichi Prefectural Board of Education, local studies material: Mochizuki Family Residence
- https://apec.aichi-c.ed.jp/kyouka/shakai/kyouzai/2018/syakai/tousan/005/005.htm
Last verified: 2026.08.31
Cultural Treasures in the Same Area
All are within walking distance in the same area, so we recommend visiting them together.
- Mochizuki Family Residence (Kuroda, Shinshiro City, Aichi) Main house 0.00 km
- Mochizuki Family Residence (Kuroda, Shinshiro City, Aichi) Kamaya 0.01 km