Kaise Family Residence Main Hall: Numazu's Oldest Surviving Home in an Izu Mountain Village
Tucked into the folds of the Izu Peninsula's northwestern mountains, in a slender hamlet strung along the Kōchi River, stands a low, broad-roofed farmhouse that has watched over its valley for at least one hundred and sixty years — and quite possibly more than two hundred. The Kaise Family Residence Main Hall (Kaiseke Jūtaku Omoya) in Nishiura Kōchi, Numazu City, is the oldest surviving dwelling in the entire city. In August 2023 it was added to the national register of Tangible Cultural Properties, recognizing both its architectural quality and the living traditions that still unfold beneath its rafters.
For travelers seeking a Japan beyond temples and castles, the house offers something rarer: an everyday building still inhabited by the same family that built it, still surrounded by the citrus groves they have tended since the Edo period, and still serving as the stage for a summer festival whose origins reach back generations.
A House Older Than the Modern Nation
The Kaise family — known by the trading name Nakaya — served as nanushi (village headman) and later kochō for the village of Kōchi from the Edo through the Meiji periods. According to family tradition, their ancestors were brothers descended from former retainers of the Takeda clan of Kai Province, who migrated here during the Sengoku era from a village called Kaise in Shinano Province. The Kaise surname and the citrus orchards on the surrounding slopes are both legacies of that long settlement.
Pinpointing exactly when the present house went up has proved difficult; no ridge tablet (munafuda) has survived to record the day of construction. Yet the hand-forged wrought-iron nails used in the long nageshi rails of the innermost room confirm a date no later than the closing decades of the Edo period. A small wooden ofuda from the Ōyama religious pilgrimage, found nailed inside the central living area, hints that the building may reach as far back as the late eighteenth century — well over two centuries old.
Why It Was Designated
The cultural property registration cites the house as a precious example of a regional headman's residence, conveying the dignified scale and spatial logic of the elite farming households of northern Izu. Three qualities stand out.
First, its architecture preserves the classic six-room (muma-dori) plan of a wealthy Izu farmhouse, with a generous earthen-floored doma to the northeast for work and cooking, and six tatami rooms arranged in two parallel rows on the southwest side. Second, although the original thatched roof was replaced with pantile around 1929, the underlying timber frame was kept intact, so visitors can still read the original carpentry — the steep pitch of the roof, intended to shed thatch, remains a giveaway of the building's earlier life. Third, the formal three-room suite along the front — Maezashiki, Nakazashiki, and Okuzashiki — is not a museum tableau but a working ritual space, used to this day during the local Tennō Festival.
Highlights to Look For
Step inside and the first thing to catch the eye is the soaring open ceiling of the doma, where the small raised ventilator roof (koshiyane) once let smoke from the sunken hearth escape. From here the small-roof framing, with its stacked beams, posts, and a remarkably steep angle for a tile roof, can be studied at a glance — a kind of cross-section of late-Edo carpentry exposed to view.
The three formal rooms unfold to the southwest, opening onto a wraparound veranda. The innermost room, the Okuzashiki, is the most refined of the three, with a tokonoma alcove and decorative shelf. Behind those shelves, family lore holds, lies a small concealed chamber said to have sheltered the attendants of visiting dignitaries — perhaps related to the documented Edo-period visits of bakufu forestry officials, who came to inspect the village's "Ohayashi" managed timberlands.
Each July, those same rooms transform. During the Kōchi Tennō Festival, a portable mikoshi shrine is enshrined in the Okuzashiki, sacred kagura dance is performed in the Nakazashiki, and spectators gather in the Maezashiki — turning the house itself into a stage for folk performing arts. The kagura tradition is said to have arrived in the late Tenpō era, brought from the Ōkawa family of nearby Mitsu when a bride from that household married into the Kaise.
The Setting and the Citrus Slopes
The hamlet of Nishiura Kōchi lies just inland from the coast of Suruga Bay, on the western side of the Izu Peninsula's base. Houses cluster on the mountainsides, kept above the floodplain of the Kōchi River, and behind them the slopes are blanketed with mandarin orchards. The Kaise family has cultivated citrus here continuously since the Edo period; a 1832 travel diary of the bakufu's pleasure-garden official Kimura Kishige already noted Kōchi's mikan as a local product. The current 21st-generation head of the family carries on the orchard.
Visitors to the area can combine a glimpse of the residence with sweeping views of Suruga Bay and Mt. Fuji from the western Izu coast, a stroll through the working orange groves, and the slow rhythms of a fishing-and-farming community largely undisturbed by mass tourism.
Visiting and Surrounding Attractions
The Kaise Family Residence is a private home and is not open as a daily-admission museum; access depends on the family's preservation activities and seasonal events. Travelers interested in visiting should consult the official site of Ippan Shadan Hōjin Nakaya in advance.
The wider Nishiura district rewards a leisurely day. The waterfront villages of Mito, Kuse, and Heda look out across Suruga Bay toward Mt. Fuji on clear days. The Numazu Deep Sea Aquarium nearby showcases creatures from one of Japan's deepest bays, and the slopes above produce some of the country's most prized winter mandarins. Combined with the historic post-town atmosphere of central Numazu and the Mishima-Numazu temple circuit, the area gives a layered sense of how the Izu base has lived for centuries from the meeting of mountain, orchard, and sea.
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Q&A
- How old is the Kaise Family Residence?
- The use of hand-forged wrought-iron nails dates the building to at least the late Edo period — over 160 years old. A surviving Ōyama pilgrimage tablet inside suggests construction may reach back to the late 18th century, potentially over 220 years old.
- What kind of cultural property is it?
- It is a National Registered Tangible Cultural Property (Building), registered on August 7, 2023. This designation recognizes structures of significant historical or architectural value that contribute to Japan's cultural landscape.
- Can I visit the residence?
- The residence is still a family home and is not a regular museum. Special openings are sometimes offered tied to preservation projects and the July Tennō Festival. Always check ahead with the owners' association before planning a visit.
- What is the Kōchi Tennō Festival?
- An annual local festival held in July at which a mikoshi is placed in the residence's innermost room and sacred kagura dance is performed in the adjacent room. The kagura tradition was reportedly transmitted from the Mitsu district during the late Tenpō era of the Edo period.
- What does the family do today?
- The family continues to grow mandarins and other citrus on the surrounding slopes, a practice that has been carried on since the Edo period. The current head is the 21st generation of the Kaise (Nakaya) line.
Basic Information
| Name | Kaise Family Residence Main Hall (海瀬家住宅主屋 / Kaiseke Jūtaku Omoya) |
|---|---|
| Location | 171-1 Nishiura Kōchi, Numazu City, Shizuoka Prefecture |
| Designation | National Registered Tangible Cultural Property (Building) |
| Date of Registration | August 7, 2023 |
| Period of Construction | Late Edo period (c. 1830–1868); possibly traceable to the late 18th century |
| Structure | Wooden, single-story, hipped roof (yosemune-zukuri), pantile (sangawara) roofing — originally thatched |
| Building Area | Approx. 223 m² |
| Owner | Ippan Shadan Hōjin Nakaya (General Incorporated Association Nakaya) |
| Access | Approx. 35 minutes by car from JR Numazu Station; bus service available to the Nishiura district |
References
- Kaise Family Residence Main Hall — Cultural Heritage Online (Agency for Cultural Affairs / NII)
- https://bunka.nii.ac.jp/heritages/detail/598890
- National Designated Cultural Properties Database — Kaise Family Residence Main Hall
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00014608
- About the Building — Kaise Family Residence Main Hall (Official Site)
- https://kaiseke.com/mainhouse
- History of the Kaise Family — Kaise Family Residence Main Hall (Official Site)
- https://kaiseke.com/history
- About Kōchi Village — Kaise Family Residence Main Hall (Official Site)
- https://kaiseke.com/kouchi
- Numazu City Cultural Property Preservation and Utilization Plan — Reference Materials
- https://www.city.numazu.shizuoka.jp/kurashi/kyoiku/kyoiku/bunka/doc/hozonkatsuyou_keikaku_shiryo.pdf
Last verified: 2026.04.19