【Make Coolness a Game】“Coolness Guarantee Plan” at Tateshina Oyayu Onsen in Nagano Boasts Sub-25°C Summer Retreat

Cooling down with negative ions near the waterfall close to Tateshina Oyayu Onsen

Oyayu Onsen Goshi Kaisha, which operates the hot spring inn 'Tateshina Oyayu Onsen Founded in Taisho 15' in Fujimi, Nagano Prefecture (Headquarters: Fujimi, Nagano; President: Yukiteru Yanagisawa), announces that its gamified 'Coolness Guarantee Plan' is already gaining popularity.

Private open-air bath surrounded by nature (30-minute free access for guests)

【Overview and Background】

While Karuizawa is widely known as a summer retreat in Nagano Prefecture, the Tateshina area of Fujimi City—home to Tateshina Oyayu Onsen—is an insider’s highland escape equally cool and refreshing. With a summer average high temperature of 26°C, guests often express surprise, saying, 'I didn’t expect it to be this cool!' Nearby, the 'Tateshina Great Falls' offers forest bathing infused with the refreshing sensation of negative ions.

Tateshina Lake, a scenic spot just a 5-minute drive from the inn

Tateshina Oyayu Onsen Founded in Taisho 15

Valley view from the 30,000-book library lounge

Although some may still be unfamiliar with Tateshina or how to pronounce it, we aim to spread awareness of its refreshing climate and invite more travelers to enjoy a comfortable summer getaway. This year, we have once again launched sales of the 'Coolness Guarantee Plan.' Even before peak summer, we’ve already welcomed 30 groups in June, clearly indicating strong demand for cool-weather retreats. To avoid overtourism at popular destinations, we hope travelers will consider Tateshina for their increasingly hot July and August getaways.

Open-air bath connected directly to the main bath, overlooking a first-class river. 'Yuyake no Ma' (Evening Glow Room), a guest room recreated after the favorite room of director Yasujiro Ozu

Tateshina Oyayu Onsen Founded in Taisho 15

Example of cold drinks offered when temperatures exceed 25°C (illustrative image)

【Coolness Guarantee Plan】

A plan that guarantees the refreshing coolness of Tateshina. We guarantee temperatures below 25°C. At noon on the day of stay, we measure the temperature using a thermometer installed at the hotel entrance. If the temperature exceeds 25°C, we apologize by offering one complimentary cold drink (choice of draft beer, white wine, or apple juice) during dinner. Whether temperatures stay below 25°C—ensuring a cool, comfortable stay—or exceed it—granting a lucky free drink—guests win either way, making this a fun, gamified experience.

Available stay period: June 1, 2026 – September 30, 2026

Reservations here

【Accommodation Offering the Coolness Guarantee Plan】

The library lounge at Tateshina Oyayu Onsen, boasting 30,000 books

'Misuzu Lounge & Bar,' the library lounge of Tateshina Oyayu Onsen

Tateshina Oyayu Onsen Founded in Taisho 15

The accommodation offering the 'Coolness Guarantee Plan' is 'Tateshina Oyayu Onsen Founded in Taisho 15,' located in Fujimi, Nagano Prefecture. This June, it celebrates its 100th anniversary. Nestled in the natural beauty of Mount Tateshina, it is a secluded retreat for adult relaxation. The inn features a 30,000-book library lounge where guests can unwind with a glass of wine.

'Tateshina Club,' guest rooms with private open-air baths, opened in February 2026

Guest rooms come in various styles, including those inspired by literary figures associated with the inn and rooms with private open-air baths. Rejuvenate at one of five scenic open-air baths along the stream, and savor mountain delicacies prepared in a Japanese-French fusion style at private dining rooms. Other unique facilities include a women-only planetarium stone spa that recreates the starry sky of Tateshina. Currently, a 100th-anniversary commemorative event is being held until May 31, 2027.

'Tenyu no Yu,' a women-only rock open-air bath. Women-only planetarium stone spa

'Tateshina Yamakuisine,' featuring abundant mountain delicacies from Nagano. Private dining rooms where guests can enjoy meals without hesitation

Tateshina Oyayu Onsen Founded in Taisho 15

【Future Developments】

The library lounge of Tateshina Oyayu Onsen, celebrating its 100th anniversary this year

In preparation for the 100th anniversary of 'Tateshina Oyayu Onsen Founded in Taisho 15' in 2026, we launched the '100th Anniversary Countdown Project' ten years ago, carrying out annual renovations and events.

Now that we’ve reached the 100th anniversary, we are hosting commemorative events offering gifts and special services for guests. Additional events and services are planned for the future.

'100th Anniversary Countdown Project' · 2016: 'Sui-Suwako,' a sister property, opened on the shores of Lake Suwa · 2017: Open-air baths along the stream, directly connected to the main bath, opened · 2018: New private dining rooms and a 30,000-book library lounge & bar added · 2019: Complete renovation of all guest rooms · 2020: Private open-air baths added to garden-courtyard guest rooms

· 2021: On-site shop reopened after renovation

· 2022: Sister property 'Kamisuwa Shinyu' reopened after full renovation

· 2023: Planetarium stone spa introduced

· 2024: 'Yuyake no Ma' and relaxation room newly established

· 2025: Renovation work began on guest rooms with private open-air baths, completed in February 2026

· 2026: Hosting events to commemorate the 100th anniversary

【Sister Properties】

'Moonlit Sakura Lounge & Bar,' where illuminated cherry blossoms shift through seven colors

A tranquil retreat by the mystical Lake Suwa Kamisuwa Shinyu

Completed full renovation in 2024. A warm, healing inn by Lake Suwa, featuring universal design elements such as private hot spring baths accessible by wheelchair.

https://www.kamisuwa-shinyu.com/

'Watasudzu,' an open-air bath with an infinity view of Lake Suwa

Sui-Suwako, a relaxing hot spring inn in Suwa

A serene retreat with private open-air baths in all 8 rooms. From the rooftop open-air bath, an infinity view unfolds where the bathtub blends seamlessly with Lake Suwa.

https://www.sui-suwako.jp/

【Oyayu Onsen Goshi Kaisha】

Operating three hot spring inns in Tateshina and Kamisuwa, Nagano. The main property, 'Tateshina Oyayu Onsen,' was founded in Taisho 15. In April 2019, as part of the 100th-anniversary countdown, the entire property was renovated to reflect the cultural heart of the region during the Meiji, Taisho, and Showa eras. As sister properties, 'Sui-Suwako' opened on the shores of Lake Suwa in June 2016, and 'Kamisuwa Shinyu,' located nearby, completed a full renovation in 2024 after remodeling the 'Yamagami' guest room.

【Company Overview】 Company Name: Oyayu Onsen Goshi Kaisha (Tateshina Oyayu Onsen Founded in Taisho 15) Representative: President Yukiteru Yanagisawa Founded: June 1926 (Taisho 15) Incorporated: October 21, 1948 (Showa 23) Headquarters: 4035 Kitayama, Fujimi, Nagano Prefecture Website: https://www.tateshina-shinyu.com/

【Inquiries】 Oyayu Onsen Goshi Kaisha Public Relations: Saori Imai TEL: 0266-67-2020 Email: [email protected]