Psoriasis & Onsen | Acidic and Sulfur Springs Officially Indicated

Ishida Onsen's source flows naturally on the flanks of Mt. Esan, an active volcano, and is piped about 2.5 km down, inheriting the spring once used by a highland hotel. The 1984 analysis shows pH 2.1 and 5.518 g/kg of dissolved solids, with 2,972 mg/kg of sulfate plus abundant aluminum and iron, in the lineage of classic alum and green-vitriol springs. Clear at the source, the water oxidizes to a cloudy yellow-brown in the bath, with a squeaky feel, sour taste and metallic scent that speak of the volcano.

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

Counted among Kusatsu's historic "Twelve Baths" since the Edo period, Kunshi no Yu is said to have been named in the Kan'ei era and still bubbles up west of the Yubatake, toward Sainokawara. Flowing naturally at 64.7 liters per minute, its clear water carries drifting white mineral flakes and a gentle sulfur aroma that distills the essence of Kusatsu.

Nestled in Kusatsu Onsen, one of Japan's three most renowned hot springs, Jizo-no-yu has been cherished since ancient times, deeply intertwined with Kusatsu's unique `yumomi` (hot water stirring) culture. This powerful spring, known for its invigorating touch, seems to cleanse away physical and mental stagnation. It provides a deep, restorative warmth that penetrates to the core, offering a refreshing sensation akin to rejuvenation after your bath. Jizo-no-yu offers solace to travelers seeking relief from persistent fatigue or skin discomfort, and those desiring an authentic hot spring experience.

Obuki is the roaring source at the heart of the steaming geothermal field of Tamagawa Onsen, on the southern slopes of Hachimantai. Its output from a single vent is often said to be the largest in Japan, and the fumarole field around it has long produced mineral deposits and the rare hokutolite stone. Every bath in the spa draws on this one source, served either straight or cut with fresh water. At pH 1.13 the water tingles sharply on the skin while warming the body to the core, and it has welcomed long-stay therapeutic bathers for generations, a spring for those who want to meet nature at full strength.

The Bandaiko source, which unexpectedly erupted from within the Bandai Sulfur Mine in 1970, now stands as Kusatsu's primary hot spring, boasting the largest output and supporting the town. Named with the wish for 'eternal prosperity' (万代), this powerful source was born in the mountains, far from the Yubatake (Kusatsu's central hot-water field). Its colorless, transparent waters deliver a stimulating tingle that awakens both mind and body, while its robust warmth permeates to the very core. This energetic spring is a perfect companion for those seeking liberation from daily routines and a crisp mental and physical rejuvenation.

This unique created hot spring utilizes the fumaroles of Owakudani, which were formed by volcanic activity approximately 3000 years ago. In the early Showa period, Hakone Onsen Kyokyu Co., Ltd. developed this source to supply hot water to areas like Sengokuhara and Gora. The water, created by mixing volcanic gas and water, offers a distinct, tingling, and tightening sensation upon contact with the skin. The powerful energy from the earth delivers restorative warmth deep into the body, a warmth that lingers long after your bath. It is ideal for those seeking deep relaxation and rejuvenation, wishing to refresh their mind and body.

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

This is one of the most well-known sources in Noboribetsu, a leading onsen destination in Hokkaido. It continuously flows at a high temperature of 96.5°C, embodying the raw power of the earth. The highly acidic water, with a pH of 2.2, provides a tingling sensation on the skin and a refreshing feeling after bathing. Its rich iron and sulfate content offers a powerful bathing experience that feels as if it's awakening both mind and body. It's a spring for those who wish to reset from daily fatigue, gain new vitality, and feel nature's energy throughout their entire being.

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

Shirahatage Genzen, located in Kusatsu Onsen and adjacent to Yubatake (Kusatsu's central hot-water field), is said to have been discovered by Minamoto no Yoritomo. Historically, it served as the stage for 'Jikan-yu' (timed bathing), supporting balneotherapy culture, and is truly considered the soul of Kusatsu. Its distinctive aroma and powerful waters, which feel as though they firm the skin, seem to awaken the mind and body from within. Surrendering to its embrace offers a pure moment to shed daily clamor and rediscover one's true self. This spring is a sanctuary for those seeking a fresh start and rejuvenation.

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

The Taenoyu Onsen (Kin no Yu) source gushes naturally in the gorge of the Sendatsu River that runs through the Nyuto Onsenkyo, and it earns the name "golden water" as its iron shifts from gold to deep brown on meeting the air. At pH 2.9 its acidic water tightens the skin while its sulfates let warmth linger in the body. It suits travelers who wish to restore body and mind in a spirited spring to the sound of the mountain stream.

Originating from the fumaroles of Owakudani, born from the eruption of Hakone volcano approximately 3,000 years ago, this artificially developed hot spring began to be supplied to Sengokuhara and Gora by Hakone Onsen Kyokyu Co., Ltd. in Showa 5 (1930). Its renowned milky white waters, blended with naturally gushing spring water, offer a pleasant sensation that tightens the skin and a powerful restorative warmth that penetrates deep into the body's core. After bathing, you'll feel surprisingly refreshed and light. It's a perfect companion when you seek to feel the Earth's energy and achieve deep relaxation and rejuvenation for your mind and body.

This spring rises at a spa retreat about 900 m up the northwest flank of the Hakkoda Mountains, amid beech forest, in the area chosen as Japan's first National Health Resort Hot Spring. It has long filled a great bathhouse built entirely of hiba cypress alongside the area's other springs. At pH 1.71 it is strongly acidic, with a tingling bite on the skin and a faint scent of sulfur and iron; sinking into its milky water feels like the essence of a traditional healing spa, especially in deep-snow winter.

Ubayu Gensen gushes naturally from fissures in acidic welded tuff at roughly 1,250 metres on the flank of Mount Dainichi in the Azuma range. Tradition holds that Endo Okura, a gold prospector, found it in 1533 after meeting a mountain crone — the yamauba whose name the source still carries. Carried down by gravity through vinyl piping and cooled in troughs that harvest sulphur flowers, its pH 2.6 waters bubble with hydrogen sulphide, tightening the skin and leaving a clean lightness behind. It suits travellers who want deep mountain stillness.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

The Yubatake source, naturally gushing from Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field), holds a distinguished history. During the Edo period, it was ranked as the highest-ranking Ozeki in the Onsen Banzuke, recognized alongside the Shirahata source as one of Kusatsu's two major hot springs. Its powerful, pH2 water, permeated with a sulfurous aroma, imparts a refreshing, tightening sensation upon the skin. A soak in this historic, renowned hot spring cleanses the body and mind, offering deep relaxation and rejuvenation from daily fatigue. It is a must-visit for those seeking to feel the energy of a historic hot spring and desire a complete refresh.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

Makukawa No.1 Source gushes naturally deep in the folds of the Azuma mountain range, beside the Makukawa stream at around 1,300 meters. Emerging at 54.2°C, the clear water mellows as it travels through the pipes, and its 154 mg/kg of metasilicic acid lends a gentle, moisturizing touch. It suits travelers who wish to unwind slowly in mountain silence.

Known for some 1,700 years and said to be one of Takeda Shingen's hidden baths, Umegashima is a mountain toji village at the head of the Abe River. The city manages the spring and distributes it to the inns. Clear yet scattered with white yunohana, its pH 9.4 alkaline water feels silky and slippery, long praised as a "bath that makes beauties" and ideal for slow, lukewarm soaks.

Hirugami's waters famously burst forth in 1973 during railway tunnel construction. Wells No. 2 to 5 followed, and today their blended "new mixed spring" is centrally managed and piped to the inns of the valley. At pH 9.8 it is strongly alkaline, giving the skin a slippery, silky feel, with a faint sulfur scent and gentle sweetness.

Bessho Onsen No.4 Source is one of the springs of Bessho Onsen, a 1,400-year-old spa some link to the "Nanakuri no yu" praised in The Pillow Book, and it is said to feed the drinking fountain at Kitamuki Kannon temple. Nearly clear, the water carries a toasty sulfur aroma and an alkaline softness that wraps the skin in a slippery smoothness. It suits travelers who want a quiet soak at the gate of an ancient temple.

Shin Awanoyu Gensen rises in Shirahone Onsen, a mountain spa village in the Northern Alps known for its milky waters. Clear at the moment it emerges, the water turns pale blue-white as it meets the air, with white mineral flakes drifting through it. At about 36°C, close to body temperature, carbon dioxide gathers on the skin as fine bubbles amid a faint sulfur scent, suiting bathers who prefer to linger for hours rather than hurry through a hot soak.

Onneyu Onsen began in 1899, when spring rights were granted at a spot the Ainu had used as a hunting lodge. Ooe Honke dates its founding to that year and uses water that the Onneyu Onsen cooperative pumps from three wells (Kumiai No. 1–3) in the Hanaoka district and blends in a mixing tank. At pH 8.8 the water is clear and smooth on the skin with a light sulfur scent, perfect for long soaks in spacious indoor and open-air baths amid the quiet mountains of the Okhotsk region.

In 1954, mineral flowers were found blooming on the banks of the Agano River, and a well was dug to open this comparatively young spa; the area's name was even changed to "Sakihana," meaning blooming flowers. Colorless when drawn, the water turns a clear yellow-green in the bath, leaving white mineral flakes on spouts and rails. A toasted, almost smoky sulfur aroma and a slick, weakly alkaline feel make it a favorite for sulfur-spring lovers.

Kintaro Onsen gushes in Tenjinno, Uozu, close to Kurobe-Unazukionsen Station on the Hokuriku Shinkansen, where the edge of an alluvial fan looks up to the Tateyama range. The Kintaro Onsen source unites the qualities of a chloride spring and a sulfur spring: a dense, hypertonic water holding 4790.0 mg/kg of sodium and 1401.0 mg/kg of calcium, with thiosulfate and free hydrogen sulfide lending a sulfur scent. White and grey mineral flakes drift through the water, suiting bathers who want a hot, deeply warming soak and lovers of both salt and sulfur.

The Sakura no Yu source rises unaided in the Nasu range, high in the Okunasu district of Omaru Onsen, delivering 189 litres a minute without a pump. The waters of this pocket of the mountains have been tended for more than two centuries, and in the Meiji era General Nogi Maresuke is said to have come each year to take the cure. Emerging at 77.9°C, the water is all but colourless and clear, neither scented nor tasting of much. Rich in metasilicic acid, it feels rounded on the skin and leaves a soft, unhurried lightness once the bathing is done. It suits anyone who wants to steep quietly, without sting or drama, in the hush of the mountains.

Amagase Onsen is one of Bungo's three great hot springs, alongside Beppu and Yufuin. The Ukihabekan Shinshiyo source is drawn via a 150-meter deep powered drill from a hillside site. With over 1,300 years of history, Amagase's waters were mentioned in the ancient "Bungo Fudoki" chronicles and have long been cherished for therapeutic bathing. This source combines pH 8.9 alkalinity with sulfur properties, gently removing old skin cells for a smooth feel. You can enjoy a silky skin sensation after bathing, perfect for those seeking to refresh mind and body.

Emerging from a tea field near the gate of Kurama-dera Temple in Kyoto's "inner parlor" during the late Meiji era, this rare and esteemed hot spring offers subtly sulfur-scented waters. Its gentle, weak alkaline touch smoothly envelops the skin, leaving it with a silky feel. After bathing, a refreshing lightness of body and mind promotes rejuvenation. It provides deep relaxation, helping to relieve pain from journeys exploring Kifune Shrine and Kurama-dera Temple, allowing visitors to deeply refresh amidst the beauty of nature through the four seasons.

The Kashio no Yu No. 1 source draws seawater-strength brine from the heart of the Southern Alps, far from any coast, and the place name Kashio, "deer salt," is said to recall deer that gathered to lick the salty water. For generations this brine has been boiled down to make mountain salt. Its dense salts and gentle sulfur aroma wrap the body, letting warmth linger long after the bath. It soothes travelers who wish to steep quietly in a rare salt spring deep in a mountain village.

Ginga no Yu, Ryusei no Yu and Hoshi no Yu are three springs that gush naturally in the national forest toward Momijidani at Sounkyo Onsen, and the blend of these three sources is piped in together. Sounkyo is a spa set in a gorge of sheer Daisetsuzan cliffs, and this blend, though hotter than 70°C, is neutral and gentle, carrying a faint hydrogen sulfide scent and an eggy taste. Its slippery touch leaves the body light, a soothing sulfur spring for anyone who wants to linger amid the gorge's wild scenery.

Sounkyo Onsen traces its roots to the Shioya hot spring opened beside the Ishikari River in the early Taisho era. The Katsura no Yu 1-2-3 mixed source wells up naturally at about 79°C from only two meters underground, is stored in a tank and piped along the mountainside to the baths. Softly scented with sulfur and silky on the skin, it leaves bathers feeling light, a fine companion for travelers unwinding beneath the gorge's towering cliffs.

A new 'Wa-modern' current emerged in Noboribetsu Onsen's history in 2006. This distinctive spring, with its faintly fragrant sulfur, evokes a sense of travel, while its chloride and sulfate composition gently infuses the skin with rich warmth. The heat gradually permeates the body's core, offering a pleasant restorative warmth that endures post-bath. It is perfectly suited for those desiring deep relaxation for mind and body in a sophisticated ambiance, far from daily clamor.

Unzen Onsen Kojigoku Source rises in Kojigoku, among Unzen's steaming "hells," where a bathhouse for toji cures is said to have opened in 1731, and the scholar Yoshida Shoin is said to have visited. Clear as it gushes, the water turns milky white in the air and soothes the skin with a sulfurous aroma. Plentiful in volume, it suits travelers seeking a rustic, unhurried soak in the Unzen highlands.

Sarugawa Onsen has long been known as a cold spring seeping naturally from the left bank of the Saru River in a national forest, with piping to the baths beginning in 1973. As the natural flow dwindled, an 80-meter well was drilled in 1997 and now feeds the baths. The pH 9.4 alkaline water carries a faint hint of sulfur and leaves skin feeling smooth, suiting skiers and campers who want to unwind in the Hidaka hills.

Nakabusa Onsen is a lone mountain inn in the Northern Alps, where legend says the general Sakanoue no Tamuramaro healed his wounded soldiers; a bathhouse opened here in 1821 alongside alum mining. With nearly 30 naturally flowing sources, each tub offers a different spring. This mixed spring feeds the Oyu bath, combining Mushiburo No. 1 and Konabetate and cooling the water by heat exchange and air rather than adding water. The alkaline water is silky enough to make the floor slippery, with a faint sulfur scent and valley views from the open-air tub.