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Yusaya Japanese Inn

元祖うなぎ湯の宿 ゆさやがんそうなぎゆのやど ゆさや

A heritage ryokan in Naruko with a color-shifting alkaline bath

Lodging

Day Use

No

Bathing & Water

Natural onsen water

Uses natural hot spring water

Outdoor BathYes

Open-air outdoor bath

Indoor BathYes

Enclosed indoor bathing area

Bathing Arrangements

Private BathYes

A private bath you can reserve for yourself or your group

The private outdoor bath is free for lodging and rest guests only; bathing-only (day-use) visitors are not admitted.

Mixed BathingNo

Shared bathing area for all genders

Baths are single sex; men's and women's baths differ in size and are swapped by time of day, not mixed bathing.

Policies & Services

WashingYes

Shower, wash stations, soap and shampoo provided

ParkingYes

On-site or nearby parking available

23 spaces (1 bus, 2 microbuses, 20 cars), free, no reservation needed, per a travel-agency listing.

Water treatment

Pure source water· 源泉かけ流し (gensen kakenagashi)
from Article 18 disclosure
  • Added water
    No
  • Reheated
    No
  • Recirculated
    No
  • Disinfected
    No
  • Bath additives
    No

新うなぎ湯3号泉・山道新1号泉・山道新2号泉・山道新3号泉・山道新4号泉・山道新5号泉・山道新6号泉混合泉

Shin-Unagiyu Spring No.3 / Sando-Shin Springs No.1–6 mixed source

Operated by · 元祖うなぎ湯の宿 ゆさや

Mixed source

Sulfur
+ Sulfate · Bicarbonate
Color
colorless and clear
Taste
with a bitter edge
Odor
strong hydrogen sulfide

Sodium Sulfate-Bicarbonate-Chloride spring

Hot source · 69°CSulfur-richHigh silica
Composition fingerprint2.1 g/kg dissolved · Hypotonic
Na⁺81
SO₄²⁻49
HCO₃⁻22
Cl⁻22
CationsAnions
Sodium Na⁺
salt's cation — pairs with chloride to make the water salty.
Sulfate SO₄²⁻
"gypsum / Glauber's salt" — vessels and wound healing.
Known good for
  • Skin conditionsatopic skin, eczema
  • Circulationtired legs
  • Aches & jointsstiff shoulders
  • Sensitive-skin cautionbroken or dry skin

A sulfur-bearing sodium sulfate-bicarbonate spring blended from the inn's own wellfield in Naruko Onsen. The wellhead runs at 68.9 °C and the bath is served with no dilution, no reheating, no recirculation and no disinfection — fully untreated source flow. At the spout the water is clear, but the air carries a strong hydrogen sulfide note and a faint bitterness lingers if tasted; once the water settles, fine mineral scale (yuno-hana) drifts up. Metasilicic acid at 184 mg/kg paired with the sulfur fraction gives the slippery 'eel-water' (unagi-yu) feel the inn is named for, and salinity sits in the mid range — about 2,077 mg/kg of dissolved solids.

Analyzed Mar 18, 2021·一般財団法人 宮城県公衆衛生協会·Cert no. 第010007号

Explore the water

Views

Forest
Mountains

About

Yusaya is a small ryokan in Naruko Onsen built around two hot-spring baths. The indoor bath, Unagi-yu (うなぎ湯, literally "eel bath"), is fed by an alkaline sulfate spring said to leave skin feeling smooth, and its color is known to shift from emerald to near-black depending on the weather. A short uphill walk from the main building, on the inn's own grounds, sits a private outdoor bath, Akane no Yu (茜の湯), reserved by time slot and free for lodging guests only; it is sometimes closed when bears are seen nearby. Baths are separated by sex, with the men's and women's sides swapped by time of day rather than mixed. The building is a nationally registered tangible cultural property, and the indoor bath is old enough to appear in writings from the mid-Edo period. Inside, a retro-modern interior keeps the feel of an old-fashioned countryside inn.

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SM
Sergey M
1 year ago

217. Yusaya Japanese Inn, Naruko Onsen An ambiguous place. I was drawn by the unique bath on a hill across the road from the ryokan, available only to guests. Stayed overnight with meals. Breakfast and dinner were generous; they gave a double portion without any issues. Dinner featured an exquisite persimmon dish. The room was spacious, but the toilet was shared in the hallway (only a sink in the room). There were some service issues: - It was cold in the room in November; the heater tried its best but shut off at night on a timer; - Breakfast started 40 minutes later than scheduled; - Couldn't leave luggage after checkout since the ryokan was closed the next day; - The shared hallway toilet situation; - Hectic checkout process for guests; - The unique hilltop bath is effectively accessible for only 25 minutes + 5 minutes to walk up/down. They give a free pass to the neighboring public onsen. The ryokan itself has been featured in magazines. The unique hilltop bath is effectively private. Each room gets a 30-minute slot (including time to walk up and down). Water in the bath is clear, temperature 39. The view of the trees is gorgeous. The bath was rightly highlighted in the magazine. The first set of indoor baths for men was available until 21:00 (M/F switch happens then). Breathing inside is comfortable. Two baths with clear, slightly cloudy water. The main bath at 40-41 and a small polygonal bath at 36. The second set consists of one old-school indoor bath, breathing is fine. Water is clear, slightly cloudy, temperature 42-43. The place has its drawbacks, but also unique features. In any case, I'd consider it as an accommodation option in Naruko Onsen. If staying multiple nights, as a nominee for one of them - it looks even more compelling.

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Last updated September 19, 2026