Kotori no Yu, a day-use hot spring in Matsushiro, Nagano City, is holding a limited-time "Chilled Onsen" (冷やし温泉) event from July 3 (Friday) to July 26 (Sunday), 2026. With record-breaking heat becoming an annual concern across Japan, this event offers a new way to enjoy hot spring bathing during the summer months without the physical strain of soaking in high-temperature water.
Three Bath Zones at Different Temperatures
During the event, guests can experience three distinct bathing zones, each set to a different temperature:
- Indoor Bath (内湯) — The classic deep-warming soak, maintained at a standard hot spring temperature
- Outdoor Bath (露天) — A summer-only naturally cool open-air bath that uses the spring water at its raw source temperature
- Viewing Outdoor Bath (展望露天風呂) — A comfortable-temperature outdoor bath with sweeping views of the surrounding scenery
Each zone is set to a different temperature level, so guests can choose whichever suits their condition or preference on the day.
Mineral-Rich Waters in a Cooler Soak
The "Chilled Onsen" experience lets guests cool down their summer-warmed bodies while still benefiting from the restorative effects of mineral-rich spring water — something a swimming pool or air-conditioned room cannot offer. Kotori no Yu's water is a blend of 皆神温泉 (Minakamiyama Onsen), which wells up on the facility's own grounds, and 松代城下温泉 (Matsushiro Castle Town Onsen), transported from within Matsushiro. The water has a gentle, skin-friendly character with a neutral pH, making it suitable for a wide range of ages.
For the "Chilled Onsen" event, the spring's mineral quality remains unchanged while the bath temperature is adjusted to a level that feels refreshing rather than hot.
Recommended Approach: Alternating Hot and Cold Bathing
The recommended way to enjoy the event is alternating hot and cold bathing (温冷交互浴), moving through each zone in sequence:
- Warm up deeply in the indoor bath
- Cool down gently in the naturally cool outdoor bath using raw spring water
- Relax and take in the Northern Alps views from the viewing outdoor bath
The combination delivers the invigorating refreshment typical of hot spring bathing alongside the open-air freedom of summer.
After Your Bath
After the baths, guests can unwind in the facility's relaxation space, which is stocked with roughly 10,000 books and comics. The adjoining café restaurant serves seasonal menu items, floats, and homemade gelato made with local Shinshu ingredients — a fitting way to round off a summer bath outing.
Event Information
Event: Chilled Onsen (冷やし温泉)
Period: July 3, 2026 (Friday) – July 26, 2026 (Sunday)
Hours: 11:00 AM – 9:00 PM (Last admission: 8:30 PM)
Venue: Kotori no Yu — Garden Outdoor Bath (庭園露天風呂)
About Kotori no Yu
Kotori no Yu is a day-use hot spring in Matsushiro, Nagano City, nestled in quiet natural surroundings at the foot of Minakamiyama Mountain. Renovated and reopened in November 2017, the facility offers panoramic views of the Zenkoji Plain from inside and features three types of baths: a viewing outdoor bath, a garden outdoor bath that changes with the seasons, and an indoor bath.
Address: 2832 Tojo, Matsushiro-machi, Nagano City, Nagano 381-1221
Official Website: https://kotorinoyu.jp/
