Kosaka Family Residence

What Is the Kosaka Family Residence?

The Kosaka Family Residence (小坂家住宅, Kosaka-ke Jūtaku) is a rural homestead on the left bank of the Chikuma River in the Murayama district of Nagano City, Nagano Prefecture, where eight structures centered on a thatched main house built in the late Edo period (1830 to 1868) were registered as Registered Tangible Cultural Properties on December 5, 2019.

Each of the eight is a separate registration: the main house, a rice storehouse, a rear warehouse, a farm equipment storehouse, a miso storehouse, a nagayamon gate, a rear gate and an earthen wall. All share the address 282 Ichinoguchi, Oaza Murayama, and all were listed under the same criterion, that of contributing to the historic landscape of the nation.

The name is not unique. A Kosaka Family Residence in Mino, Gifu Prefecture, and the Former Kosaka Family Residence in Setagaya, Tokyo, are different buildings with their own histories.

A Family of Village Headmen and Weir Keepers

According to Nagano City's cultural property database, the Kosaka were farmers who served as village headmen (nanushi) during the Edo period. Living beside a river that flooded and fed the fields in equal measure, they also held posts such as sekimori, the keepers of the weirs who managed flood defense and the allocation of irrigation water. In the modern era the family stayed prominent, supporting local industry and culture, and one of its members went on to sit in the national Diet.

The buildings of the Kosaka Family Residence map that working life onto the ground. There is a storehouse for rice, one for miso, one for farm tools, a gatehouse for receiving visitors, and a ring of storehouses drawn tight around the main house.

The oldest dated structure is the rice storehouse, which carries an ink inscription of 1855. The main house also belongs to the late Edo period. The nagayamon gate and miso storehouse followed in the early Meiji era (1868 to 1882), and the rear warehouse, farm equipment storehouse, rear gate and earthen wall in the late Meiji era (1898 to 1912). Read in sequence, the dates show a homestead assembled over roughly half a century.

How the Kosaka Family Residence Is Laid Out

The main house stands in the middle of the plot facing south, and everything else guards the edges. Approaching from the east, you meet the formal front first: the nagayamon gate sits at the center of the eastern boundary, and the miso storehouse is joined to its southern end, so the two read as one long, solid facade.

At the southwest corner the rice storehouse runs north to south. From there the earthen wall turns a right angle along the west and north sides and ends at the rear warehouse. Along the north edge, from west to east, stand the rear warehouse, the rear gate and the farm equipment storehouse, a quieter back elevation that contrasts with the ceremonial east front.

The clearest way to take in the Kosaka Family Residence is to trace its perimeter in that order: gate and miso storehouse, then the rice storehouse, the wall, and finally the three northern structures. The character of the property shifts from public to private as you go. Each building has its own page with details of construction.

Visiting the Kosaka Family Residence

The Kosaka Family Residence is still a privately owned home and is not open to the public. Visitors cannot enter the grounds or the buildings, and as of September 2026 no public opening days or admission fees appear in Nagano City's published information. What you can see is limited to views from outside the property, chiefly the gate and miso storehouse on the east side, visible from the road.

The nearest station is Yanagihara on the Nagano Electric Railway's Nagano Line; the residence lies roughly 500 meters east of the station in a straight line. The surrounding area is a mix of houses and farmland with some narrow lanes, and no visitor parking could be confirmed. Please do not stop cars in front of the property or peer into the family's daily life, and keep any photography to the exterior as seen from the public road.