Former Koshi Family Residence

The Silk King's House

The Former Koshi Family Residence (旧越家住宅, Kyū-Koshike Jūtaku) is a Meiji-era silk-reeling family's house in the Harukicho area of Suzaka City, Nagano Prefecture, whose main house and two storehouses were registered as Registered Tangible Cultural Properties on September 19, 2003 (Agency for Cultural Affairs). All three belong to Suzaka City, and together with three other sites registered the same day they were among the city's first registered cultural properties (Suzaka City).

The house is tied to Koshi Jusaburo, remembered in Suzaka as its "silk king." According to the city, he acquired the property around 1905-06 and remodelled it for his son Yasuzo. The city's own note from the time of registration puts the purchase and remodelling at around 1912, so two dates are in circulation.

Koshi's company, Yamamaru-gumi, was among the first in town to install a telephone, and its number was 1. That is why the house is also known as Yamamaru Ichibankan, "Yamamaru Number One" (Suzaka City).

Yamamaru-gumi and a Silk Town

The surrounding block once belonged to Yamamaru-gumi. The city says the company's head office stood just south of the house, with a reeling mill and a stroll garden beyond. At its height the firm ran mills in Suzaka, in what is now Saitama City and in Anjo in Aichi Prefecture, and employed 8,000 people, making it one of Japan's leading silk producers.

When an American silk industry mission visited Suzaka in 1919, it was entertained in this house (Suzaka City); Go NAGANO, the prefecture's tourism site, says the guests were received in the broad reception rooms. In 2007 the Ministry of Economy, Trade and Industry listed the house among its Heritage of Industrial Modernization.

Suzaka was an early center of machine reeling driven by waterwheels, and of Tokosha, a cooperative that shipped raw silk jointly. On August 15, 2024, the Suzaka district was selected as an Important Preservation District for Groups of Traditional Buildings of the "silk-reeling town and merchant town" type, and the city lists the Former Koshi Family Residence among the buildings open to visitors there (Suzaka City).

How the Property Is Laid Out

The main house fronts the street, with two storehouses behind it (Suzaka City). The Agency records that the main house runs long from east to west, facing south, with its east gable end turned to the street. The Inner Storehouse joins the west end of the house through a small room in front of its door, and the Outer Storehouse stands to the southwest; together the two frame the back of the lot.

• Main House: timber, 2 storeys, tiled roof, building area 280 square metres (registration number 20-0138)
• Inner Storehouse: Dozo-zukuri storehouse, 2 storeys, tiled roof, building area 20 square metres (20-0139)
• Outer Storehouse: dozo-zukuri storehouse, 2 storeys, tiled roof, building area 33 square metres (20-0140)

All three were registered for their contribution to the historic landscape of the nation (Agency for Cultural Affairs).

Sources disagree on dates. The Agency places the main house in the mid-Meiji period, with a gabled west wing added late in Meiji, and dates both storehouses to late Meiji. Suzaka City's description instead estimates the main house to be early Meiji, and of the storehouses dates the southern one to early Meiji and the northern one to the Taisho era, after Koshi took over the property. Each building is covered on its own page.

Visiting

Suzaka City acquired the house in 1998, and it is now looked after by the Kyū-Koshike Fureai Club, a group of Harukicho residents, as a base for community activities. Admission is free, and visitors can walk through the rooms and look out over the garden (Suzaka City).

From April to October it is open 9:30 a.m. to 5:00 p.m., and from November to March 10:00 a.m. to 4:00 p.m., with last entry 30 minutes before closing. It is closed December 29 to January 3 (Suzaka City, checked October 2026).

The house is about 700 metres east of Suzaka Station on the Nagano Electric Railway in a straight line, and the city's page shows a parking area. Many buildings in the surrounding preservation district are private homes, and the city asks walkers to be considerate of residents.