Onsen ryokan and hotels in Gunma
Every onsen stay in Gunma we can back with data: onsen analysis reports and facility details checked against the property’s own pages.
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Stays in Gunma
75 stays- 45With analysis report
- 15Free-flowing
- 44In-room open-air bath
- 37Reservable private bath
- 5Tattoos OK in shared baths
- 5Mixed bath
- Sulfur Spring15 stays黄
- Chloride Spring14 stays塩
- Acidic Spring11 stays酸
- Sulfate Spring4 stays硫
- pH 1.7–8.8
Spring type and pH come from the main source of the 45 stays whose analysis report we have on file.
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
Sensuikan
Kusatsu, Gunma
- Reservable private bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring · Free-flowing
pH 2.2See the spring data ›Sources & details
- Analysis report on file
- Free-flowing (posted notice)
- Private bath checked Oct 2026
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 183 mg/kg
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
Uribou Ryokan
Kusatsu, Gunma
- Reservable private 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
Uribou Ryokan Nakatoori Urahou
Kusatsu, Gunma
- Reservable private 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
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
Kishigon Tatsu No Yu
Ikaho, Gunma
- 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: private bath (kishigon.co.jp) · Checked May 31, 2026
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 Hinoki Tei Bokusuii
Kusatsu, Gunma
- Reservable private bath
酸Acidic Spring · Chloride spring
pH 1.75See the spring data ›Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Acidic Hydrogen Sulfate and Chloride Hot Spring (Hypotonic Acidic high-temperature hot spring) / Metasilicic acid 528.3 mg/kg
Kusatsu Onsen Pension Goroji
Kusatsu, Gunma
- Reservable private 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 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 Itouyen Hotel Kusatsu
Kusatsu, Gunma
- Reservable private bath
酸Acidic Spring · Chloride spring
pH 1.75See the spring data ›Sources & details
- Analysis report on file
- Private bath checked Oct 2026
Spring type: Acidic Hydrogen Sulfate and Chloride Hot Spring (Hypotonic Acidic high-temperature hot spring) / Metasilicic acid 528.3 mg/kg
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 Sen
Kusatsu, Gunma
- Reservable private 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: private bath (travel.rakuten.co.jp) · Checked May 30, 2026
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
Oedo Onsen Monogatari Premium Ikaho
Ikaho, Gunma
- Tattoos OK if covered
Property's note: Guests with tattoos are not permitted to use the public bath. However, use is allowed if tattoos are completely covered with a designated cover sticker (available for a fee) provided by the facility.
塩Chloride Spring
pH 6.4See the spring data ›Sources & details
- Analysis report on file
- Tattoo rule checked Oct 2026
Spring type: Calcium-Sodium Sulfate, Bicarbonate and Chloride Hot Spring / Recirculated or disinfected / Water added / Metasilicic acid 181 mg/kg
Source: tattoo rule (ooedoonsen.jp) · Checked May 31, 2026
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
Yukawa Terrace
Kusatsu, Gunma
- Reservable private 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
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
Kusatsu Onsen Maebashikan
Kusatsu, Gunma
- Reservable private bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring
PRIncludes affiliate linksView rates on Rakuten TravelSources & 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 Ichii
Kusatsu, Gunma
酸Acidic Spring · Chloride spring · Free-flowing
pH 1.7See the spring data ›Sources & details
- Analysis report on file
- Free-flowing (posted notice)
Spring type: Acidic Hydrogen Sulfate and Chloride Hot Spring / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 528.3 mg/kg
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
Moriaki Ryokan
Ikaho, Gunma
- 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 / Metasilicic acid 181 mg/kg
Source: private bath (jalan.net) · Checked May 30, 2026
Tajimaya Ryokan
Kusatsu, Gunma
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 242.7 mg/kg
Kamenoihoteru Kusatsurizoto
Kusatsu, Gunma
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
Hoshi Onsen Chojukan
Minakami, Gunma
硫Sulfate Spring · Alkaline (pH 7.5+) · Free-flowing
pH 8.5See the spring data ›Sources & details
- Analysis report on file
- Free-flowing (posted notice)
Spring type: Calcium-Sodium Sulfate Hot Spring / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 40.6 mg/kg
Kusatsu Onsen Bouun
Kusatsu, Gunma
酸Acidic Spring · Chloride spring · Free-flowing
Sources & details
- Analysis report on file
- Free-flowing (posted notice)
Spring type: Acidic Aluminum Sulfate and Chloride Hot Spring / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 277.9 mg/kg
Oyado Konoha
Kusatsu, Gunma
- Reservable private bath
黄Sulfur Spring · Acidic (pH under 3) · Chloride spring
pH 2.1See the spring data ›Sources & details
- Analysis report on file
Spring type: Acidic Sulfur-containing Aluminum Sulfate and Chloride Hot Spring / Metasilicic acid 225 mg/kg
Source: private bath (dormy-hotels.com) · Checked May 30, 2026
Kusatsu no Oyado Kiyoshigukan
Kusatsu, Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Forest Resort Conifer Iwabitsu
Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Shima Onsen Hinatami-kan
Shima Onsen, Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 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
Manza Prince Hotel
Manza & Tsumagoi, Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
- Private bath checked Oct 2026
Source: private bath (princehotels.co.jp) · Checked May 31, 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
Kin Yu Kan
Annaka, Gunma
硫Sulfate Spring · Free-flowing
Sources & details
- Analysis report on file
- Free-flowing (posted notice)
Spring type: Calcium Sulfate Hot Spring / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 37.6 mg/kg
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
Kusatsu Kan
Kusatsu, Gunma
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; Hypotonic Acidic high-temperature hot spring) / Free-flowing from the source, with no added water, heating or recirculation / Metasilicic acid 240.6 mg/kg
Shima Tamura
Shima Onsen, Gunma
塩Chloride Spring
pH 6.69See the spring data ›Sources & details
- Analysis report on file
Spring type: Sodium-Calcium Chloride and Sulfate Hot Spring / Free-flowing, with heating, added water or filtering / Water added / Metasilicic acid 175 mg/kg
Hotel Kozan So
Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
Source: private bath (kohzansou.com) · Checked May 31, 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
Manza Onsen Nisshinden
Manza & Tsumagoi, Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
Source: private bath (yukoyuko.net) · Checked May 30, 2026
Oigami Onsen Kinryuen
Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
Source: private bath (travel.rakuten.co.jp) · Checked May 30, 2026
Roijin Onsen Goro-kaku
Gunma
- Reservable private bath
No onsen analysis report on file yet
Sources & details
Source: private bath (travel.rakuten.co.jp) · Checked May 30, 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
Yujuku Onsen
Minakami, Tone District, Gunma
硫Sulfate Spring · Alkaline (pH 7.5+)
PRIncludes affiliate linksView rates on Rakuten TravelSources & details
- Analysis report on file
Spring type: Sodium-Calcium Sulfate Hot Spring / Free-flowing, with heating, added water or filtering / Water added / Metasilicic acid 60.6 mg/kg
Takaragawa Onsen Osenkaku
Minakami, Gunma
No onsen analysis report on file yet
Sorted using onsen analysis reports and what each property states on its own or booking-site page.
A stay is listed when we have its onsen analysis report on file, or when we checked its private open-air baths, reservable private baths or tattoo rules against its official website or booking-site page. Stays with neither are left out. Lists for each onsen town are under “More onsen towns” below.
- This list includes stays whose onsen analysis report we have on file, and stays whose facility details we checked against a source. Stays with neither are left out.
- 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.