A Three-Storey Timber Hall Built for Silkworms
The First Silkworm Rearing House of Ehime Sanshu Co., Ltd. (愛媛蚕種株式会社第１蚕室, also transliterated Ehime Sanshu Kabushiki-gaisha Dai-ichi Sanshitsu) is a three-storey wooden building at 3-70 Kawanoishi, Honai, Yawatahama City, Ehime Prefecture, completed in 1919 (Taisho 8) and entered on Japan's national Register of Tangible Cultural Properties on 7 June 1999. It stands on a long, north-south lot on rising ground, extending northward from the company's office and entrance block, and it remains the property of Ehime Sanshu Co., Ltd.
The business behind it is older than the building. Agency for Cultural Affairs records identify the founder as Hyodo Torajiro, a kimono-fabric merchant in the town who moved into sanshu, the production of silkworm eggs, under the trade name Nisshinkan. Yawatahama City dates the founding to 1884. Local accounts add that Hyodo had sent his daughter a few years earlier to a sericulture training institute in Uwajima, the first of its kind in the prefecture, and that father and daughter began the work together once she had learned to rear the worms and take the eggs. The firm was reconstituted as Ehime Sanshu Co., Ltd. in 1946.
Silkworm eggs are an agricultural product, which makes their appearance in a busy coastal shipping town slightly unexpected. Kawanoishi in the Meiji and Taisho years was a place where money and technology arrived early: the prefecture's first bank opened here in 1878, and Shikoku's first spinning mill followed in 1887. A commercial egg producer fitted that pattern of enterprise rather well, and the company still makes and sells silkworm eggs today, described by Yawatahama City as the only such producer left in the prefecture.
Why the Building Was Registered
Registration came in the seventeenth round of the national register, under registration number 38-0005, with the gazette notice following on 19 July 1999. The criterion applied was contribution to the historic landscape of the country. The Agency for Cultural Affairs classifies it under primary industry, one building, of timber, three storeys, tiled roof, with a building area of 210 square metres.
It was not registered alone. Three structures on the same lot went on the register together on the same day: the office and entrance block of the late Meiji period (38-0004), this First Rearing House (38-0005), and the Second Rearing House immediately to the north (38-0006). Reading them as a sequence is the point. An office in Western dress faces the corner of the street, and behind it the working halls run back and uphill, each one added as the business grew.
What gives the rearing house its structural interest is the roof. The Agency's description singles out a sturdy king-post truss, a Western carpentry system that carries the span on a single central post with paired diagonal struts. Adopting it meant the floors below could be left broad and free of intermediate posts, which is exactly what a rearing room needs when trays of worms have to be moved, checked and rotated by hand. Prefectural descriptions of the registered group note the same combination throughout: Japanese building practice at the joinery, Western engineering where the loads are, and old glass still in the openings, rippled enough to bend the view.
What to Look For from the Lane
The east elevation is the face that does the work. Along the street side, board doors are set in across the entire length of the building, and above them the glazing continues upward as far as the underside of the beam. The result is a wall that can be opened almost completely or shut almost completely, which is the practical answer to a room where temperature, air movement and light all have to be held within narrow limits. Walk the lane and the building reads as a long band of timber below and a long band of glass above, repeated on each of the three floors.
Inside the plan, a corridor runs down the west side on every floor. Circulation is kept off to one side so that the rearing rooms themselves stay uninterrupted.
Practical matters are worth stating plainly. Ehime Sanshu is a working company rather than a museum, and there is no published scheme for admitting visitors to the interiors. The exteriors of the three registered buildings can be seen from the public lane, which is where their character is most legible in any case. Photographing the buildings from the road is unproblematic; anything beyond that should be asked about first. Guided walks of the Kawanoishi district are run by the Honai volunteer guide association, based at the Minase community facility a few minutes away at 3-11-1 Kawanoishi, and are arranged by advance booking.
Getting here means starting from JR Yawatahama Station on the Yosan Line, then taking a local bus toward Honai; the site is roughly ten minutes on foot from the Honai Chosha-mae stop. Once you are in the district, the rest of it is walkable. The red brick warehouse of the former Toyobo mill, the Minase Bridge of 1933, the Western-style former Shiraishi Watarō residence and the registered Uchinoura Public Hall of 1937 all sit within a short circuit, and the walls of slag brick produced at the Sajima smelter turn up along the lanes between them.
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Q&A
- Can visitors go inside the First Silkworm Rearing House of Ehime Sanshu?
- Not as a matter of course. The building belongs to an operating company and there is no published visiting scheme or admission fee. The exterior is visible from the public lane at any time. If you want to understand what you are looking at, book a walk in advance with the Honai volunteer guide association at the Minase facility in Kawanoishi.
- When was the First Silkworm Rearing House of Ehime Sanshu built, and when was it registered?
- It was built in 1919, the eighth year of the Taisho era. Registration as a national Tangible Cultural Property took effect on 7 June 1999, with the public notice issued on 19 July of that year, under registration number 38-0005.
- What is architecturally unusual about the First Silkworm Rearing House of Ehime Sanshu?
- Two things. The roof is carried on a heavy king-post truss, imported Western engineering that keeps the rearing floors clear of intermediate posts. And the street elevation combines full-length board doors with continuous glazing above them, giving the operator fine control over light and ventilation across the whole east wall.
- How do you reach the First Silkworm Rearing House of Ehime Sanshu?
- Take the JR Yosan Line to Yawatahama Station, then a local bus toward Honai. From the Honai Chosha-mae bus stop the site is about a ten-minute walk. Drivers should note that the buildings sit down a narrow lane and are easy to pass without noticing.
- How does the First Silkworm Rearing House of Ehime Sanshu relate to the other registered buildings on the site?
- Three buildings were registered together on 7 June 1999: the late Meiji office and entrance block (38-0004), this hall (38-0005), and the Second Rearing House to the north (38-0006). The office faces the street corner, the two rearing halls run back from it along the slope, and a brick firewall separates the first hall from the second.
Basic Information
| Name | First Silkworm Rearing House, Ehime Sanshu Co., Ltd. (愛媛蚕種株式会社第１蚕室) |
|---|---|
| Location | 3-70 Kawanoishi, Honai-cho, Yawatahama City, Ehime Prefecture |
| Designation | Registered Tangible Cultural Property (Structure), registration no. 38-0005 |
| Year Designated | Registered 7 June 1999; gazetted 19 July 1999 (17th registration round) |
| Quantity | 1 building |
| Dimensions | Timber, three storeys, tiled roof; building area 210 m² |
| Owner | Ehime Sanshu Co., Ltd. |
| Public Access | Interior not open to the public; exterior visible from the adjoining lane. District walks by advance booking through the Honai volunteer guide association. |
References
- National Cultural Properties Database, Agency for Cultural Affairs: First Silkworm Rearing House, Ehime Sanshu Co., Ltd.
- https://kunishitei.bunka.go.jp/heritage/detail/101/00001146
- Cultural Heritage Online: First Silkworm Rearing House, Ehime Sanshu Co., Ltd.
- https://online.bunka.go.jp/heritages/detail/177366
- National Cultural Properties Database, Agency for Cultural Affairs: Office and Entrance, Ehime Sanshu Co., Ltd.
- https://kunishitei.bunka.go.jp/heritage/detail/101/00001145
- Yawatahama City: The Meiji Townscape of Honai
- https://www.city.yawatahama.ehime.jp/doc/2014091200025/
- Honai Townscape Guide: Introduction to Honai and Its Industries
- https://www.honaimachinami.com/town-introduction/
Last verified: 2026.08.04