Ryokan with an open-air bath in the room in Gunma
Stays in Gunma where you can soak in an onsen bath on your own room’s terrace.
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Stays in Gunma
44 stays
Naraya
Kusatsu, Gunma
- Rooms with private open-air bath
- Reservable private bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring · Free-flowing
Sources & details
- Tattoos OK if covered
- Analysis report on file
- Free-flowing (posted notice)
- Private bath checked Oct 2026
- Tattoo rule checked Oct 2026
Spring type: Acidic Sulfur-containing Aluminum Sulfate and Chloride Hot Spring (hydrogen sulfide type; Hypotonic Acidic high-temperature hot spring) / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 240.6 mg/kg
Source: in-room bath (kusatsu-naraya.co.jp) · private bath (kusatsu-naraya.co.jp) · tattoo rule (kusatsu-naraya.co.jp) · Checked May 31, 2026
Oyado Tamaki
Ikaho, Gunma
- Rooms with private open-air bath
- Reservable private bath
Property's note: Guests with tattoos are strictly prohibited from using the public bath. Please use rooms with open-air baths or private baths (additional charge) if you have tattoos. However, guests with small, single-point tattoos that can be completely covered by a sticker may use the public bath. Please ask the front desk for stickers.
塩Chloride Spring
pH 6.4See the spring data ›Sources & details
- Tattoos OK if covered
- Analysis report on file
- Tattoo rule checked Oct 2026
Spring type: Calcium-Sodium Sulfate, Bicarbonate and Chloride Hot Spring / Metasilicic acid 181 mg/kg
Source: in-room bath (travel.rakuten.co.jp) · private bath (oyado-tamaki.com) · tattoo rule (oyado-tamaki.com) · Checked May 31, 2026
Kusatsu Now Resort Hotel
Kusatsu, Gunma
- Rooms with private open-air bath
- Reservable private bath
Property's note: Guests with tattoos are not permitted to use the public baths or swimming pool. Private baths (for a fee) are available. Tattoos are permitted if completely covered. Cover-up stickers were available for purchase.
酸Acidic Spring · Chloride spring
pH 1.75See the spring data ›Sources & details
- Tattoos OK if covered
- Analysis report on file
- Tattoo rule checked Oct 2026
Spring type: Acidic Hydrogen Sulfate and Chloride Hot Spring (Hypotonic Acidic high-temperature hot spring) / Metasilicic acid 528.3 mg/kg
Source: in-room bath (travel.yahoo.co.jp) · private bath (travel.rakuten.co.jp) · tattoo rule (kusatsu-now.jp) · Checked May 31, 2026
Hotel Tenbo
Ikaho, Gunma
- Rooms with private open-air bath
- Reservable private bath
塩Chloride Spring
pH 6.4See the spring data ›Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Calcium-Sodium Sulfate, Bicarbonate and Chloride Hot Spring / Metasilicic acid 181 mg/kg
Source: in-room bath (tenbo.com) · private bath (tenbo.com) · Checked May 31, 2026
La Vista Kusatsu Hills
Kusatsu, Gunma
- Rooms with private open-air bath
- Reservable private bath
酸Acidic Spring · Chloride spring · Free-flowing
pH 2.4See the spring data ›Sources & details
- Analysis report on file
- Free-flowing (posted notice)
Spring type: Acidic Aluminum-containing Chloride Hot Spring / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 166 mg/kg
Source: in-room bath (dormy-hotels.com) · private bath (g-onsen.hatenablog.com) · Checked May 30, 2026
Libmax Resort Kusatsu Onsen
Kusatsu, Gunma
- Rooms with private open-air bath
酸Acidic Spring · Chloride spring · Free-flowing
pH 1.75See the spring data ›Sources & details
- Analysis report on file
- Free-flowing (posted notice)
- Private bath checked Oct 2026
Spring type: Acidic Hydrogen Sulfate and Chloride Hot Spring (Hypotonic Acidic high-temperature hot spring) / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 528.3 mg/kg
Shima Yamaguchi-kan
Shima Onsen, Gunma
- Rooms with private open-air bath
塩Chloride Spring · Alkaline (pH 7.5+) · Free-flowing
pH 7.6See the spring data ›Sources & details
- Analysis report on file
- Free-flowing (posted notice)
- Private bath checked Oct 2026
Spring type: Sodium-Calcium Chloride and Sulfate Hot Spring / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 105 mg/kg
Source: in-room bath (yamaguchikan.co.jp) · Checked May 31, 2026
Gensen Yu no Yado Matsunoi
Minakami, Gunma
- Rooms with private open-air bath
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Tattoos OK if covered
- Tattoo rule checked Oct 2026
Source: in-room bath (5star-ryokan.com) · private bath (spa.or.jp) · tattoo rule (ooedoonsen.jp) · Checked May 30, 2026
Ikaho Onsen Hotel Kimura
Ikaho, Gunma
- Rooms with private open-air bath
Onsen analysis report on file
Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Neutral Cold Mineral Spring / Recirculated or disinfected / Water added / Metasilicic acid 66.1 mg/kg
Source: in-room bath (travel.rakuten.co.jp) · Checked Oct 27, 2026
Ikaho Onsen Hotel Kogoro
Ikaho, Gunma
- Rooms with private open-air bath
塩Chloride Spring
pH 6.4See the spring data ›Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Calcium-Sodium Sulfate, Bicarbonate and Chloride Hot Spring / Metasilicic acid 181 mg/kg
Source: in-room bath (travel.rakuten.co.jp) · Checked Oct 27, 2026
Irori no Oyado Hanashiki no Yu
Nakanojo, Agatsuma District, Gunma
- Rooms with private open-air bath
塩Chloride Spring · Alkaline (pH 7.5+)
pH 7.9See the spring data ›Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Calcium-Sodium Sulfate and Chloride Hot Spring / Recirculated or disinfected / No water added / Metasilicic acid 49.9 mg/kg
Yamada Ya Onsen Ryokan
Manza & Tsumagoi, Gunma
- Rooms with private open-air bath
- Reservable private bath
塩Chloride Spring
pH 7.2See the spring data ›Sources & details
- Analysis report on file
Spring type: Sodium-Magnesium Chloride, Sulfate and Bicarbonate Hot Spring / Free-flowing, with heating, added water or filtering / No water added / Metasilicic acid 129 mg/kg
Source: in-room bath (spa.or.jp) · private bath (spa.or.jp) · Checked May 31, 2026
Shima Onsen Kashiwaya Ryokan
Shima Onsen, Gunma
- Rooms with private open-air bath
塩Chloride Spring · Alkaline (pH 7.5+)
pH 7.5See the spring data ›Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Sodium-Calcium Chloride and Sulfate Hot Spring / Metasilicic acid 100 mg/kg
Kusatsu Onsen Tenojiya
Kusatsu, Gunma
- Rooms with private open-air bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring · Free-flowing
Sources & details
- Analysis report on file
- Free-flowing (posted notice)
Spring type: Acidic Sulfur-containing Aluminum Sulfate and Chloride Hot Spring (hydrogen sulfide type) / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 208 mg/kg
Source: in-room bath (travel.rakuten.co.jp) · Checked May 30, 2026
Kusatsu Onsen Hotel Sakurai
Kusatsu, Gunma
- Rooms with private open-air bath
酸Acidic Spring · Chloride spring · Free-flowing
pH 1.75See the spring data ›Sources & details
- Analysis report on file
- Free-flowing (posted notice)
Spring type: Acidic Hydrogen Sulfate and Chloride Hot Spring (Hypotonic Acidic high-temperature hot spring) / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 528.3 mg/kg
Source: in-room bath (hotel-sakurai.co.jp) · Checked May 31, 2026
Kusatsu Onsen Juninya Ryokan
Kusatsu, Gunma
- Rooms with private open-air bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring
Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Acidic Sulfur-containing Aluminum Sulfate and Chloride Hot Spring (hydrogen sulfide type) / Metasilicic acid 242.7 mg/kg
Kusatsu Onsen Yubatake Sensuimizu
Kusatsu, Gunma
- Rooms with private open-air bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring
Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Acidic Sulfur-containing Aluminum Sulfate and Chloride Hot Spring (hydrogen sulfide type) / Metasilicic acid 242.7 mg/kg
Kusatsu Onsen Yubatake Soan
Kusatsu, Gunma
- Rooms with private open-air bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring
Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Acidic Sulfur-containing Aluminum Sulfate and Chloride Hot Spring (hydrogen sulfide type) / Metasilicic acid 242.7 mg/kg
Kusatsu Onsen Urakusatsu Tou
Kusatsu, Gunma
- Rooms with private open-air bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring
Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Acidic Sulfur-containing Aluminum Sulfate and Chloride Hot Spring (hydrogen sulfide type; Hypotonic Acidic high-temperature hot spring) / Metasilicic acid 234.1 mg/kg
Tange Onsen Misatokan
Nakanojo, Gunma
- Rooms with private open-air bath
- Reservable private bath
硫Sulfate Spring · Alkaline (pH 7.5+)
pH 8.8See the spring data ›Sources & details
- Analysis report on file
Spring type: Calcium Sulfate Hot Spring / Free-flowing, with heating, added water or filtering / No water added / Metasilicic acid 23.5 mg/kg
Source: in-room bath (spa.or.jp) · private bath (spa.or.jp) · Checked May 31, 2026
Yuyado Tokinoniwa
Kusatsu, Gunma
- Rooms with private open-air bath
- Reservable private bath
酸Acidic Spring · Chloride spring
pH 2.4See the spring data ›Sources & details
- Analysis report on file
Spring type: Acidic Aluminum Sulfate and Chloride Hot Spring / Metasilicic acid 165 mg/kg
Source: in-room bath (ikyu.com) · private bath (dormy-hotels.com) · Checked May 31, 2026
Fukuichi
Ikaho, Gunma
- Rooms with private open-air bath
- Reservable private bath
塩Chloride Spring
pH 6.4See the spring data ›Sources & details
- Analysis report on file
Spring type: Calcium-Sodium Sulfate, Bicarbonate and Chloride Hot Spring / Free-flowing, with heating, added water or filtering / No water added / Metasilicic acid 181 mg/kg
Source: in-room bath (jtb.co.jp) · private bath (fukuichi.jp) · Checked May 31, 2026
Betutei Senjuan
Minakami, Gunma
- Rooms with private open-air bath
- Reservable private bath
塩Chloride Spring · Alkaline (pH 7.5+)
pH 8.4See the spring data ›Sources & details
- Analysis report on file
Spring type: Calcium-Sodium Sulfate and Chloride Hot Spring / Free-flowing, with heating, added water or filtering / No water added / Metasilicic acid 43.6 mg/kg
Source: in-room bath (senjyuan.jp) · private bath (travel.rakuten.co.jp) · Checked May 31, 2026
Ikaho Akeno-ya
Ikaho, Gunma
- Rooms with private open-air bath
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Source: in-room bath (travel.yahoo.co.jp) · private bath (travel.yahoo.co.jp) · Checked Oct 28, 2026
Ikaho Onsen Kanouya
Ikaho, Gunma
- Rooms with private open-air bath
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Source: in-room bath (cable-yado.com) · private bath (cable-yado.com) · Checked Oct 27, 2026
Ikaho Onsen Todoroki
Ikaho, Gunma
- Rooms with private open-air bath
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Source: in-room bath (travel.rakuten.co.jp) · private bath (travel.rakuten.co.jp) · Checked Oct 28, 2026
Ikaho Onsen Ryokan Sakurai
Ikaho, Gunma
- Rooms with private open-air bath
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Source: in-room bath (ikaho-sakurai.com) · private bath (ikaho-sakurai.com) · Checked Oct 28, 2026
Shima Onsen Jizake no Yado Nakamuraya
Shima Onsen, Gunma
- Rooms with private open-air bath
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Source: in-room bath (travel.rakuten.co.jp) · private bath (travel.rakuten.co.jp)
Sekizen Kan
Shima Onsen, Gunma
- Rooms with private open-air bath
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Source: in-room bath (sekizenkan.co.jp) · private bath (sekizenkan.co.jp) · Checked May 30, 2026
Kounkaku
Ikaho, Gunma
- Rooms with private open-air bath
塩Chloride Spring
pH 6.4See the spring data ›Sources & details
- Analysis report on file
Spring type: Calcium-Sodium Sulfate, Bicarbonate and Chloride Hot Spring / Metasilicic acid 181 mg/kg
Source: in-room bath (travel.rakuten.co.jp) · Checked May 31, 2026
Shima Onsen Itoen Hotel Shima
Shima Onsen, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Shima Onsen Shima Grand Hotel
Shima Onsen, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Shima Onsen Tokiwasure no Yado Kaigen
Shima Onsen, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Shima Onsen Toyoshimaya
Shima Onsen, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Minakami Onsen Keisetsu no Yado Syoubun
Minakami, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Minakami Onsen Bettei Yaeno
Minakami, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Minakami Tanigawa Onsen Ryokan Tanigawa
Minakami, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Kusatsu Onsen Yuyado Iwafuji
Kusatsu, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Yubiso Onsen Nakaya Ryokan
Minakami, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Roijin Onsen Ginshotei Awashima
Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Shiriyaki Onsen Hoshi ga Oka Yama So
Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
PRIncludes affiliate linksView rates on Rakuten TravelSources & details
- Private bath checked Oct 2026
Ikaho Grand Hotel
Ikaho, Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
Source: in-room bath (itoenhotel.com) · Checked May 31, 2026
Haruna Ko Onsen Yuusuge
Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
Source: in-room bath (travel.rakuten.co.jp) · Checked May 31, 2026
Roijin Onsen Sengo
Gunma
- Rooms with private open-air bath
No onsen analysis report on file yet
Sources & details
Source: in-room bath (senkyou.jp) · Checked May 30, 2026
Sorted using onsen analysis reports and what each property states on its own or booking-site page.
- Rooms with a private open-air bath
- The bath is part of your guest room (kyakushitsu rotenburo). Usually only some room types have one, so check the room type when you book.
The water in a room’s bath may come from a different source, or be heated or recirculated differently, than the shared baths. Even for stays with an analysis report, ask the property how the in-room bath is supplied.
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A stay is listed only when its official website or booking-site page says some rooms have a private open-air bath. Usually only certain room types have one, so check the room type when you book.
- Private bath and tattoo information comes from each property's official website or other published information. Every item links to its source and shows the date we last checked it. Items we could not source are left out.
- Spring type, pH and how the water is used come from the onsen analysis report that Japanese law requires each facility to post, and from the facility's water-usage notice. They are shown only for stays whose report we have on file.
- Details can change after we check them. Please confirm with the property before you book, especially tattoo rules and private bath fees.
- Booking buttons are affiliate links. They do not affect which stays are listed.