Right Onsen › Gunma › Annaka
Kami-Masuda Onsen Toride-no-Yu
4.1★ · 353 Google ratings · Annaka, Gunma · 上増田温泉 砦乃湯
✓ Day visitors✓ Outdoor bath✓ Sauna
Before you go
Can you bathe here?
Day visitors
✓ YesReported by two visitors
Hours
11:00–19:00From the facility's listing
Closed
WednesdayWeekly closing days from the listing
Tattoos
? Call aheadNo policy stated in the 36 recent reviews we read
Price
¥800 adultConfirmed by recent visitor reports
Time limit
3 hours (800 yen); full-day pass 1000 yenConfirmed by recent visitor reports
How we know this
- Day visitors: This is a day-trip hot spring facility (higaeri onsen), commonly used by hikers. · 2 visitors, Aug 2025 – Dec 2025
- Price: Standard admission is ¥800 for a 3-hour visit; since a May 2025 update, a full-day pass costs ¥1000. · 5 visitors, May 2025 – Jun 2026
- Time limit: Standard entry is time-limited to 3 hours; a 1-day pass is available for ¥1000. · 5 visitors, May 2025 – Jun 2026
The bath
What you’ll find
A small, remote mountain day-spa with genuine unheated flow-through indoor spring water (39C, pH 8.0, weakly alkaline and slippery) plus a heated outdoor tub, a weekend-only sauna, an on-site restaurant of inconsistent quality and hours, and a history of ownership changes and temporary closures.
Bath setup
Indoor baths
1.0Reported by one visitor
Outdoor bath
✓ YesAn outdoor bath exists, but under the current owner its area has been cut to under half its former size and depth reduced about 20% (kerosene heating cost cited); reviewers also report ants and horseflies and unclear rust/mold debris in the tub.Confirmed by recent visitor reports
Sauna
✓ YesA sauna exists but only operates weekends/holidays and shuts off as early as 17:00-18:00; one reviewer measured a low 76-78C and warned the resulting cold-plunge shock could be risky for elderly visitors.Confirmed by recent visitor reports
Cold bath
✓ YesA cold plunge bath exists.Reported by two visitors
View
ForestReported by two visitors
Spring water
Spring type
weakly alkaline, slipperyReported by one visitor
Source temperature
39°CConfirmed by recent visitor reports
Bath temperature
41°CThe heated outdoor tub runs around 41C, though many reviewers describe the overall bath (especially indoors) as lukewarm/tepid (nurui), so expect a cool soak rather than a hot one.Confirmed by recent visitor reports
pH
pH 8Reported by one visitor
Free-flowing (kakenagashi)
Partly confirmedFresh spring water flows continuously through the bath
Heated
PartialReported by two visitors
Water added
✕ NoReported by two visitors
How we know this
- Indoor baths: One indoor bath. · 1 visitor, Oct 2025
- Outdoor bath: An outdoor bath exists, but under the current owner its area has been cut to under half its former size and depth reduced about 20% (kerosene heating cost cited); reviewers also report ants and horseflies and unclear rust/mold debris in the tub. · 6 visitors, Jun 2025 – Jul 2026
- Sauna: A sauna exists but only operates weekends/holidays and shuts off as early as 17:00-18:00; one reviewer measured a low 76-78C and warned the resulting cold-plunge shock could be risky for elderly visitors. · 5 visitors, May 2025 – May 2026
- Cold bath: A cold plunge bath exists. · 2 visitors, Oct 2025 – Mar 2026
- View: The facility sits surrounded by mountain forest, giving a quiet, natural setting. · 2 visitors, Aug 2025 – Oct 2025
- Spring type: The spring is described as weakly alkaline with a soap-like slippery feel on the skin. · 1 visitor, Aug 2025
- Source temperature: The spring source itself is measured at about 39C. · 3 visitors, Aug 2025 – Jun 2026
- Bath temperature: The heated outdoor tub runs around 41C, though many reviewers describe the overall bath (especially indoors) as lukewarm/tepid (nurui), so expect a cool soak rather than a hot one. · 3 visitors, Dec 2025 – Jun 2026
- pH: The water is reported to have a pH of 8.0. · 1 visitor, Oct 2025
- Free-flowing (kakenagashi): The indoor bath is genuine flow-through spring water with no heating or added water, but the outdoor tub is separately heated (see 'heated' field), so only part of the facility is true kakenagashi. · 5 visitors, Jun 2025 – Jul 2026
- Heated: One review describes the spring as entirely unheated and undiluted, but another clarifies this applies to the indoor bath only (39C, straight from source) while the outdoor tub is artificially heated to about 41C. · 2 visitors, Aug 2025 – Dec 2025
- Water added: The indoor bath water is not diluted with added water. · 2 visitors, Aug 2025 – Oct 2025
Practical
What you need
Facilities
Rest area
✓ YesA tatami rest room is available and spacious, but in cold months the changing room and rest room have had inadequate heating (one visitor said the unheated changing room felt risky for elderly bathers' heat-shock).Confirmed by recent visitor reports
Restaurant
✓ YesAn on-site restaurant exists but is unreliable: it has been closed during off-season/weekday visits, seems to mainly run weekends, and reviews split between praise (ginger pork set, tanmen) and complaints of high prices and poor quality.Confirmed by recent visitor reports
How we know this
- Rest area: A tatami rest room is available and spacious, but in cold months the changing room and rest room have had inadequate heating (one visitor said the unheated changing room felt risky for elderly bathers' heat-shock). · 4 visitors, Jun 2025 – Jan 2026
- Restaurant: An on-site restaurant exists but is unreliable: it has been closed during off-season/weekday visits, seems to mainly run weekends, and reviews split between praise (ginger pork set, tanmen) and complaints of high prices and poor quality. · 9 visitors, May 2025 – Jul 2026
Timing
When to go
Weekly hours
| Day | Hours |
|---|---|
| Monday | 11:00–19:00 |
| Tuesday | 11:00–19:00 |
| Wednesday | Closed |
| Thursday | 11:00–19:00 |
| Friday | 11:00–19:00 |
| Saturday | 11:00–19:00 |
| Sunday | 11:00–19:00 |
Closed Wednesday.
Getting there
How to get there
Nearest station
Yokokawa · JR East4.4 km in a straight line; bus or taxi from the station
Address
2164 Matsuidamachi Kamimasuda, Annaka, Gunma 379-0211From the facility's listing
Show a driver
上増田温泉 砦乃湯The name in Japanese, for a taxi or at the counter
Phone
+8127-329-6798Japanese-speaking. For tattoos or private baths a call is the only sure answer
Website
toride-yu.jpOfficial, in Japanese
The map loads only when you ask for it and connects your browser to Google.
Nearby
Other baths close by
Myōgi Fureai Plaza / Myōgi Onsen Hot Spring ‘Momiji no Yu’
3.9★ · 8.2 km · Tomioka
✓Day useTattoos ?✓Outdoor bath✓Sauna
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Questions
Common questions
Can I visit Kami-Masuda Onsen Toride-no-Yu without staying overnight?
This is a day-trip hot spring facility (higaeri onsen), commonly used by hikers.
How much does Kami-Masuda Onsen Toride-no-Yu cost?
Standard admission is ¥800 for a 3-hour visit; since a May 2025 update, a full-day pass costs ¥1000.
Is the water free-flowing spring water?
The indoor bath is genuine flow-through spring water with no heating or added water, but the outdoor tub is separately heated (see 'heated' field), so only part of the facility is true kakenagashi.
