A Plaster-Walled Merchant House on the Old Hokkoku Road
Follow the old Hokkoku Kaidō east through the town of Komoro and the modern shopfronts give way to something heavier and older: a broad two-storey townhouse, its upper walls and the undersides of its eaves cased in thick white plaster, a raised plaster band running like a sash beneath the roofline. People here call it the Honmachi Machiya-kan. It went up in 1923, the twelfth year of the Taishō era, for a family who traded under the shop name Shimizuya and brewed miso and soy sauce in these rooms until the late 1960s.
The house stands in Honmachi, the central block of what was once Komoro-juku, a post town on the highway that carried travellers and freight between the Nakasendō and the Japan Sea coast. Komoro City owns the building now and runs it as a free exhibition and meeting hall. A visitor can step in off the street and stand on the floor where soy sauce was once measured out and sold.
Reading the Building: the Nuriya-zukuri Style
The construction is nuriya-zukuri, a method that wraps the timber frame in lime plaster as a guard against the fires that periodically tore through Japanese merchant streets. It stops short of the fully encased kura storehouse, yet the purpose is the same: fireproofing carried off as dignity. Those plastered flanks and eaves, and the band of plaster circling the upper wall, give the Shimizuya its solid, almost guarded face.
The scale is generous for a townhouse, roughly thirteen and a half metres across the front and close to eleven deep, under a gabled roof of pantiles. Upstairs a twenty-mat room faces the street, with two eight-mat rooms ranged behind it. The details that fix the date in the 1920s rather than the Edo period are easy to miss at first: the wide panes of glass set into the shopfront, the measured rhythm of the wooden lattice, and the low, deliberately restrained second storey that follows the local roofline along Honmachi.
Why It Is a Registered Cultural Property
The Machiya-kan holds the status of tōroku yūkei bunkazai, a Registered Tangible Cultural Property. The term is worth pausing on, because it is not the same thing as a National Treasure or an Important Cultural Property. Japan introduced this register in 1996 as a lighter form of protection, aimed mainly at buildings from the Meiji period onward, roughly half a century old or more, that lend a place its historic character. Where the older "designation" system tends to freeze a structure, registration is meant to keep it in working use; an owner may repair and adapt it within agreed limits. The house entered the register on 18 October 2006.
The standard it satisfies is plainly stated: it contributes to the historic landscape of the country. What that means on the ground is that the Shimizuya survives as a readable piece of a Taishō commercial street, the kind of substantial brewing-merchant's house that once lined post roads across this region and has largely disappeared. A deeper layer of history sits beneath it. In the early Edo period this same plot held the toiyaba, the relay station that mustered the porters and packhorses moving goods along the highway, which placed it at the working centre of Komoro-juku.
What to Look for Inside
Admission costs nothing, and the interior rewards an unhurried look. Just inside the entrance is the doma, the earthen-floored work space, where the merchant's chōba, the low railed counter from which the family kept its books, has been left in place. Set into the floor you can still find the iron cart rails once used to trundle barrels and stock through the brewery. Few houses keep so unvarnished a record of the work that went on indoors.
The site has gathered up a handful of other fragments of the town's past. In the adjoining rest hall a portable shrine, the Takehaya mikoshi, stands on permanent display, and an upstairs room holds salvaged timbers and material from the Nakajikiri-mon, one of the inner gates of Komoro Castle. Behind the house a small garden, nicknamed the Miharashi-niwa or "vista garden", opens toward the bulk of Mt. Asama, with a lawn, a wooden deck and a pavilion to rest in.
In late winter the building takes a leading part in the Komoro-juku Doll Walk, when households and shops along the old road set out their hina dolls for visitors. It is one of the better moments to catch the rooms dressed and busy.
Around the Old Castle-and-Post Town
Komoro is unusual in having been two things at once, a castle town and a highway post town, and the short walk from the station takes in both. The anchor is Kaikoen, the park laid over the ruins of Komoro Castle, three minutes away on foot. The castle is the celebrated ana-jiro, the "hollow castle": almost alone among Japanese fortresses, its keep stood lower than the town around it, with the gorge of the Chikuma River doing the work of a moat. Sengoku Hidehisa rebuilt it into a proper stronghold in the 1590s and raised a three-tier keep roofed in gold-leaf tiles; lightning burned the keep in 1626, and today only the rough-stacked stone base survives. In 1926 the forester Honda Seiroku, who shaped the plantings of Tokyo's Meiji Shrine grounds and Hibiya Park, remade the site as a public park, now counted among Japan's hundred finest places to see cherry blossom.
The poet and novelist Shimazaki Tōson taught at the local school here for six years and wrote some of his best-loved verse about this upland landscape; a memorial museum to him stands inside Kaikoen. Back along Honmachi-dōri, the old highway still keeps a scatter of merchant houses, soba shops and former inns, among them Kumeya, a one-time secondary inn reopened as a lodging, and the gate of Kōgaku-ji temple, carried here from the castle in 1872.
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Q&A
- Is there an admission fee, and when is it open?
- Viewing the house is free. It is open 9:00 to 17:00 (until 16:00 from December through March). It closes on Mondays, on the day after a public holiday, and over the New Year period from 29 December to 3 January.
- How do I get there?
- It is about a five-minute walk from Komoro Station, served by the Shinano Railway and JR Koumi Line. From Tokyo, take the Hokuriku Shinkansen to Karuizawa and change to the Shinano Railway (about 25 minutes to Komoro), or to Sakudaira and change to the JR Koumi Line (about 15 minutes). The Shinkansen itself does not stop at Komoro.
- How long should I allow, and what can I pair it with?
- The house itself takes twenty to thirty minutes. It sits within an easy walk of Kaikoen and the old Honmachi street, so it works well as one stop on a half-day stroll through the former castle town.
- When is the best time to visit?
- Late February into March brings the Komoro-juku Doll Walk, with hina-doll displays through the old shops. Spring is also when the cherry trees at nearby Kaikoen are at their height, making it a natural time to combine the two.
- What does "Registered Cultural Property" mean here?
- It is a lighter category of protection than a National Treasure or Important Cultural Property. Introduced in 1996, registration is designed for buildings, often from the modern era, that enrich a town's historic landscape and can stay in everyday use. That is exactly why this house can function as an active exhibition and event hall.
Basic Information
| Name | Komoro City Hokkoku Kaidō Honmachi Machiya-kan |
|---|---|
| Location | 2-2-9 Honmachi, Komoro, Nagano Prefecture |
| Designation | National Registered Tangible Cultural Property (Building); registered 18 October 2006 (registration no. 20-0298) |
| Built | 1923 (Taishō 12) |
| Structure | Wood, two storeys, gabled pantile roof, nuriya-zukuri (plaster-clad); building area approx. 160 m²; one building |
| Former use | Shimizuya, a miso and soy sauce brewery |
| Owner | Komoro City |
| Admission | Free (viewing) |
| Hours | 9:00–17:00 (to 16:00 December–March) |
| Closed | Mondays; the day after a public holiday; 29 December–3 January |
| Access | About 5 minutes on foot from Komoro Station (Shinano Railway / JR Koumi Line) |
| Tel | 0267-25-2770 |
References
- 国指定文化財等データベース（文化庁）｜小諸市北国街道ほんまち町屋館
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00005816
- 文化遺産オンライン｜小諸市北国街道ほんまち町屋館
- https://bunka.nii.ac.jp/heritages/detail/185723
- 小諸市オフィシャルサイト｜北国街道ほんまち町屋館(概要)
- https://www.city.komoro.lg.jp/soshikikarasagasu/sangyoushinkoubu/shokokankoka/4/2/1/879.html
- 小諸市オフィシャルサイト｜ほんまち町屋館 利用案内
- https://www.city.komoro.lg.jp/soshikikarasagasu/sangyoushinkoubu/shokokankoka/4/2/1/842.html
- 北国街道ほんまち町屋館（公式サイト）
- https://machiyakan.com/
- 八十二文化財団｜信州の文化財 小諸市北国街道ほんまち町屋館
- https://www.82bunka.or.jp/bunkazai/detail.php?no=5269
- こもろ観光局｜小諸城址・懐古園
- https://www.komoro-tour.jp/spot/castle/
Last verified: 2026.06.20