Since its opening in 1915, Hoshino Onsen has been loved as a famous hot spring in the summer resort of Karuizawa. It is said that many cultural figures, such as Hakushu Kitahara and Akiko Yosano, also immersed themselves in the water. Hoshino Onsen Tombo-no-yu is a drop-in hot spring that draws on the history of Hoshino Onsen. While feeling the forest with your whole body, you can relax your mind and body in the ancient hot springs and fully nourish your energy.
All baths at Tombo-no-Yu are fed by natural hot spring water.
The baths are filled with high-quality hot spring water from Hoshino Onsen, and its soft water is said to be "water for beautiful skin." As proof that the hot spring water is fresh, there is also a tap for drinking the water. The water is not circulated or added to, and is changed daily.
The indoor bath, open-air bath, and pond are all connected in a continuous line, and the changing time and seasons are reflected on the water's surface. The interior is made with natural materials, with an abundance of cypress and natural stone. The indoor bath is deep enough for you to immerse yourself comfortably up to your shoulders (90cm deep for men, 85cm deep for women). Enjoy the comfort of being surrounded by nature in a space that blends in with the surrounding forest.
The sauna is heated to a temperature of approximately 85-90 degrees. Every 20 minutes, water is poured into the heat source, creating a gentle steam. You can enjoy the seasonal scenery through the window while listening to jazz music in the background. The cold bath uses spring water from the Wild Bird Forest, and is kept at a stable temperature of approximately 13 degrees all year round. After working up a sweat, we recommend taking an outdoor bath in the clear air of Karuizawa.
You can enjoy the changing seasons to the fullest, with cherry blossoms and budding in spring, deep green in summer, autumn leaves in fall, and snow in winter. Seasonal baths are also held, such as an apple bath in autumn and a yuzu bath for the winter solstice. At the entrance to both the men's and women's baths, you will find "Shinra Hyakusen." These calligraphy and paintings convey the richness of the nature surrounding Tombo no Yu, and change with the seasons.
Simple hot spring (hypotonic slightly alkaline high temperature spring)
400 liters per minute
Chronic lower back pain, sensitivity to cold, recovery from fatigue, etc.
The adjacent Café Hungry Spot offers seasonal drinks, craft beer, soft serve ice cream, and more. It is recommended as a resting place or a meeting place.
After taking a bath, why not sit on a bench in the shade of a tree and take a breather while feeling the highland breeze?
0267-44-3580
April to November, New Year's holiday (4/11 to 12/29):
Adult 1,550 Yen
Children 1,050 yen
December to March:
Adult 1,350 Yen
Children: 800 yen
Indoor bath, open-air bath, sauna, cold bath, drinking spring
Body soap, shampoo, conditioner, lotion, milky lotion, cleansing wash (women's bath), hair dryer, baby bath, towels (rental towel set 350 yen, purchased bath towel 200 yen),
Use of electronic devices such as smartphones
Please refrain from using smartphones in the changing rooms and baths. They may be used at the entrances to both the men's and women's baths.
Bathing while intoxicated
Bathing for those with tattoos
However, you can only enter the bath if your tattoos can be covered with the eight designated cover stickers. The cover stickers are 8 x 10 cm in size. Please purchase them at the reception.
Bathing with children of the opposite sex
Boys aged 7 and over should use the men's bath, and girls should use the women's bath.
Use of the bath by people wearing diapers
Please use the baby bath provided for infants.
Use of hair dye
The use of hair dyes (including color treatments and hair manicures) is strictly prohibited in the changing rooms, baths, and restrooms.
In addition, any behavior that may cause inconvenience to other guests or that may soil or damage the facilities is prohibited.
Please wash your body before entering.
Please tie long hair and avoid letting it get in the bathtub.
After using the sauna, please thoroughly rinse off the sweat before entering the cold bath or bathtub.
Please do not soak the towel in the bathtub.
Please refrain from taking up space in the shower or sauna.
Tombo-no-yu is a day trip hot spring facility. You can use it regardless of whether you are staying overnight or not.
Re-entry is possible within 4 hours on the same day. Details will be provided at the Tombo-no-yu reception counter.
Only bathing suits designed to cover scars from surgeries or other wounds are allowed for. However, we do not provide them for rental.
Hoshino Area
In session 2025/12/19～2026/1/12の毎日、1/24～3/8の金土日祝(2/11除く）
In session 2025/12/12 ~ 2026/3/31
Hoshino Community Base
In session 2025/11/29、12/26、2026/1/31、2/27、3/14
Area map
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