A Changing Room With a Doubled Roof
Just south of the cave-bath entrance at Ōana stands a small single-storey building raised on a tall concrete base. This is the changing room, or datsuiba, that served the bath below it. It is modest in plan, about 25 square metres, but almost everything about its surface is unusual. The gabled roof is thatched with cedar bark, then thatched again with a second layer of cedar bark laid over the first. The outer walls are finished in cedar bark as well. From a short distance the whole thing reads as one shaggy, russet-brown volume growing out of its concrete footing.
Step inside and the structure explains itself. The interior divides into two rooms, and overhead a king-post truss is left fully exposed, its timbers carrying the weight of that heavy double roof. The wood is local: cedar from the Minakami mountains, used in quantity and left to show. The building carries the formal name Hiroike Chikuro Ōana Kinenkan Datsuiba and dates, like the bath, to 1937, with repairs in 2003.
The Room Where a Life Ended
This changing room is not registered only for its carpentry. The Ōana site is where Hiroike Chikuro died, on 4 June 1938, in a plain hut beside the upper reaches of the Tone River. The account kept by the foundation places his death in the late morning, among family and close attendants, after years of illness that he had come to these springs to ease. The changing room stands among the structures that framed those final months, which is why it is described as a commemorative building rather than merely a utilitarian one.
When it was entered on the register of Tangible Cultural Properties on 13 March 2025, the criterion cited was its contribution to the historic landscape of the country. That is a way of saying the building matters partly because of where it stands and what it stands for. The cedar-bark surfaces, the exposed truss, the tall foundation lifting it clear of the damp ground all belong to a particular place and a particular story, and the register treats them as worth keeping together.
What to Look For
Look first at the roof. A single layer of cedar-bark thatch is already uncommon; two layers, one over the other, is the kind of choice you notice once it is pointed out and cannot unsee. Then look up inside at the king-post truss. Rural bathhouses rarely put their structure on display like this, and the honesty of it fits the man commemorated here, who is remembered for prizing substance over show.
The changing room, the cave bath and the preserved deathbed room sit within a few steps of one another, so a visit takes them in as a single sequence rather than as separate stops. The Ōana and Tanigawa memorial centres are free to enter and open in general from 7:00 to 16:00, with irregular closing days. Because the buildings are small and the site quiet, this is a place for slow looking rather than a quick photograph.
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Q&A
- Why is a changing room a cultural property?
- For two reasons: its distinctive double cedar-bark roof and exposed king-post truss, and its place among the Ōana buildings connected with Hiroike Chikuro, who died at this site in 1938.
- What is a king-post truss?
- A triangular roof frame with a central vertical post rising from a horizontal tie beam to the ridge. Here it is left visible inside rather than hidden above a ceiling.
- Why cedar bark rather than tile or shingle?
- Cedar was abundant in the Minakami mountains, and the bark cladding gives the buildings their rustic, unified look. The choice of local material is part of what earned the registration.
- Can I go inside?
- The building is shown as part of the Ōana Memorial Center. Confirm current viewing arrangements with the site, since these small structures are managed for preservation.
- When was it built?
- In 1937, the same year as the cave bath it served, with repair work in 2003. It was registered as a Tangible Cultural Property in March 2025.
Basic Information
| Name | Hiroike Chikuro Ōana Kinenkan Datsuiba (changing room) |
|---|---|
| Location | 735-1 Takadaira, Ōana, Minakami, Tone District, Gunma Prefecture |
| Category | Registered Tangible Cultural Property (structure); registered 13 March 2025 |
| Registration No. | 10-0362 |
| Built / Repaired | 1937; repaired 2003 |
| Structure | Wood, single storey, cedar-bark roof; floor area about 25 m²; one building |
| Owner | Moralogy Institute for Moral Education |
| Access | Free entry; generally open 7:00–16:00, irregular closing days |
References
- National Database of Cultural Properties (Agency for Cultural Affairs) — Ōana Kinenkan Datsuiba
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00015288
- Cultural Heritage Online — Ōana Kinenkan Datsuiba
- https://online.bunka.go.jp/heritages/detail/596732
- Moralogy Institute for Moral Education — notice of registration
- https://www.moralogy.jp/post-44265/
- Moralogy Institute for Moral Education — advisory report on registration
- https://www.moralogy.jp/post-43868/
Last verified: 2026.07.04