Nasu Highlands Area

I Looked Into Koun-so

2026-09-07

I Looked Into Koun-so

On this blog, I've been running a series where I gradually look into not just campgrounds, but also inns that could come in handy on days when you think, 'Let's skip the camping and go do a hotel-cation instead.'

This time I looked into Koun-so, located in the Shiobara hot spring area of Tochigi. It seems to be a rare type of hot spring inn that not only uses its own continuously flowing spring water but also allows drinking the spring water, which caught my interest even as an indoor type.

The Short Version

This inn seems to be appealing for its continuously flowing spring water rich in metasilicic acid, a beauty-skin component, and its private baths that can be used almost around the clock.
The Rakuten Mobile signal came back with a rating of C, so if you rely on your connection, it might be worth being a little cautious.

I've summarized the details below.

I Looked Into Koun-so's Spring Source and Drinking Fountain

This inn is located in the Shiobara hot spring area of Nasushiobara City, Tochigi Prefecture, and apparently uses two spring sources: its own source called the Koun-so source, and a municipal source called Monzen No. 1. What especially caught my attention is that this water is used in a continuously flowing style with no reheating or recirculation, and it has an abundant flow rate of around 200 liters per minute. It's classified as a sodium chloride-bicarbonate spring, with a water temperature of 73.8°C and a neutral pH of 6.7. The water is said to be almost colorless and transparent, with a faint salty taste.

Another thing that caught my interest is that this spring has received permission for drinking from the regional public health center. It seems only a small number of sources in the Shiobara hot spring area are approved for drinking, and here you can apparently actually drink the water at a fountain set up next to the footbath. It's said to be suited for chronic digestive issues, chronic constipation, diabetes, gout, and liver disease, while being contraindicated for people with kidney disease, high blood pressure, or swelling, so if you're concerned about your health condition, it might be reassuring to check in advance. The metasilicic acid content, known as a beauty-skin component, is also said to rank among the highest in the country, giving me the impression that the water itself is a major feature of this inn.

Komorin
Komorin

The whole idea of drinking hot spring water wasn't something I'd ever considered, so it felt refreshing to learn about it. Since there are apparently some contraindications, if you're interested, it seems best to listen to the explanation on-site before trying it.

Private Baths, In-House Facilities, and What Caught My Eye as an Indoor Type

In addition to separate large baths for men and women, there's apparently a large open-air bath called Koun no Yu (meaning "Bath of Good Fortune"), along with private baths that each come with an indoor bath and an open-air bath. The private baths don't require reservations, and as long as they're free, you can apparently use them anytime from 2 PM check-in until 9 AM the next morning. That seemed like a setup where you could enjoy the hot spring at your own pace without worrying about crowds. For indoor types like me who'd rather relax without worrying about other people around, that might be a welcome point. There's also a footbath available.

There seem to be several room types, including Japanese-Western style rooms with their own continuously flowing spring bath, modern Japanese-Western rooms, and Japanese-style rooms with a 12-mat main room plus an 8-mat adjoining room. The entire building is apparently non-smoking, including heated tobacco products, with a smoking area set up in a corner of the first-floor lobby. As for pets, other than service animals such as guide dogs and assistance dogs, none are allowed to accompany guests or stay overnight, so if you're thinking of bringing a pet, it's worth keeping that in mind. The dining area, called Goshikigumo, along with a gift shop and banquet hall, are also apparently on the first floor, giving me the impression that the building is set up so you can spend your whole stay without needing to leave.

As for accommodation rates, I couldn't find specific pricing listed on the main official website, and it seems to vary depending on external booking sites and plans. Reservations can apparently be made through the official website's booking page, via LINE, or by phone. I couldn't find any mention on the official website about whether day-use bathing is available, so if that's something you're curious about, contacting the inn directly seems like the surest way to find out.

Rakuten Mobile Signal Conditions

When I checked the address corresponding to Koun-so's location in the Shiobara area of Nasushiobara City using Rakuten's official "My Area Coverage Simulation" tool, the overall rating came back as C. Perhaps because the area is a hot spring town nestled in the mountains, it seems like a good idea to check the connectivity situation in advance.

During a hot spring trip, you'd probably want to spend time away from your phone anyway, but if you need to stay reachable for work, it might be reassuring to prepare in advance with this rating in mind.

Komorin
Komorin

Hearing a C rating makes me brace myself a little, but maybe times like this are exactly when it's nice to just soak in the hot spring and forget about your phone.

Wrapping Up

To sum it all up, Koun-so left me with the impression of being a hot spring inn whose appeal lies in its continuously flowing water rich in metasilicic acid, a beauty-skin component, and private baths that are easy to use freely for long stretches of time. Including the fact that you can drink the spring water, it felt like an inn that really puts thought into the water itself. The Rakuten Mobile signal condition rated C, so if connectivity is a concern for you, it might be reassuring to prepare yourself mentally in advance.

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