Kosaka Family Residence (Mino City, Gifu Prefecture)

The Kosaka Family Residence: A Working Sake Brewery in a Town of Firewalls

Walk down Nibanmachi street in Mino and the Kosaka house tells you what it does before you read a single sign. A cedar ball hangs above the entrance, the centuries-old signal that fresh sake has been pressed inside. Behind the black-plastered facade, the Kosaka family has brewed under the name Hyakushun since 1772, drawing well water filtered through the gravel beds of the nearby Nagara River. The brewery still operates. The building it occupies is the only nationally designated Important Cultural Property in Mino's old merchant quarter.

The Agency for Cultural Affairs dates the main house to 1773, the second year of the An'ei era, and lists it as a single building of timber construction. The dating rests on physical evidence uncovered during a 1983 dismantling repair: the oldest of the prayer tablets nailed at the entrance is from 1773, an ink inscription on a second-floor pillar of the rear sake storehouse reads 1772, and a roof tile from the malting room carries a scratched date of the same year. Some local records, reading later prayer tablets, place parts of the house a generation on, into the 1790s. What the sources agree on is the family that built it. The Kosaka, then trading as Sugimotoya, received a brewing licence from the Owari Tokugawa domain and put up a house meant to last.

Why the House Was Designated

Mino grew rich on two trades, paper and sake, and its wealthier merchants advertised that wealth on their rooflines. The town's signature feature is the udatsu, a short firewall raised one level above the eaves at the ends of a roof. Its practical job was to stop a fire jumping from one timber house to the next along a crowded street. Its social job was louder. Only a prosperous household could afford to build one, which is why the Japanese phrase udatsu ga agaranai, literally "unable to raise an udatsu," still means to be stuck, unable to get ahead in life.

The Kosaka residence was designated an Important Cultural Property on 3 February 1979 as a representative surviving example of a merchant house in the Mino region. Inspectors singled out several things. The frontage runs about 11.4 metres and the depth about 16 metres, with a low-eaved two-storey front and a gabled roof set at a step where the rear section drops to a lower line. The roof itself curves. Rather than the straight or concave pitch common in eastern Japan, the Kosaka roof swells outward in a gentle convex arc called mukuri, a refinement associated with the Kamigata region around Kyoto and Osaka and with buildings as elevated as the Katsura Imperial Villa. The eaves are built out on projecting brackets in the segai style, and the whole front is finished in black lime plaster.

The plan drew attention too. A half-bay-wide strip runs through the boundary between the upper and lower rooms, an arrangement the designation report notes as distinctive. Taken together, the low second-storey front, the convex roof, and the firewalls make the house a textbook of how a successful Edo-period merchant in this part of Japan chose to build.

What to Look For

Start with the udatsu, because the Kosaka version breaks the local pattern. Most udatsu in Mino are capped with an onigawara, a heavy ornamental ridge-end tile, often carrying the household crest. The Kosaka firewalls have none. In its place sits a feature called toribusuma flanked by a pair of gable tiles on each side and finished with a plain gegyo, the small pendant that hangs at the gable peak. The effect is older and quieter than the showier udatsu a few doors down. Compare it with the more elaborate firewall on the nearby Imai house and the difference in restraint becomes clear.

Then step back and read the roofline. The mukuri curve is subtle and easy to miss until you look along the ridge against the sky. On a working brewery it is an unusual flourish, the kind of detail a family spent money on to mark its standing. Up close, the black plaster and the low, shuttered second-floor windows give the front a guarded, formal face.

Inside, the house is still a brewery rather than a museum set piece. The earthen-floored entrance opens into spaces where rice was once steamed and where the kettle and hearth remain in use. The sake storehouses behind the main building, some dating to the Edo period and others to Meiji, are still working structures. A reservation-only tasting room lets visitors compare the brewery's labels, and bottles of Hyakushun and the drier Sanyahō are sold on site. One small touch ties the building to the town around it. In a place famous for paper, some of the cedar balls that brewers traditionally hang are here made of Mino washi instead of cedar sprigs.

Around the Kosaka Residence

The house sits inside the Mino-machi preservation district, a stretch of Edo and Meiji merchant houses that Japan protects as an Important Preservation District for Groups of Traditional Buildings. Walking the street is the point. Roof after roof carries its udatsu, and a short illustrated guide near the district maps how each family's firewall differs in crest, tile, and pendant.

A few minutes' walk away, the Old Imai Family Residence serves as the Mino Museum. The Imai were paper wholesalers, and the house explains the trade that made the town. Mino is the home of honminoshi, the handmade paper recognised in 2014 as a UNESCO Intangible Cultural Heritage, and shops along the street sell washi and washi crafts. In autumn the district hosts the Mino Washi Akari Art exhibition, when paper lamps fill the streets after dark. For a different view, climb to Ogura Park on the wooded hill above town, the former site of a castle built by the warlord Kanamori Nagachika, or walk to the Mino Bridge, an early modern suspension bridge over the Nagara that is itself a designated cultural property.

The simplest approach is by rail. The Kosaka residence is about an eight-minute walk from Mino-shi Station on the Nagaragawa Railway.