Hakone Kowakien (located at 二ノ平1297, Hakone-machi, Ashigarashimo-gun, Kanagawa; General Manager: Satoru Shibata) is rolling out a variety of summer content in 2026, including an anime collaboration event with Demon Slayer: Kimetsu no Yaiba, the Hakone Kowakien Okinawa Haisai Festival, and hands-on participation programs led by staff — catering to a wide range of interests from "fandom travel" to "educational travel." Hakone Kowakien is a resort close to the Tokyo metropolitan area where guests can unwind, deepen bonds, and enjoy a fulfilling summer holiday.
Demon Slayer: Kimetsu no Yaiba Comes to Yunessun This Summer
Hakone Kowakien Yunessun (hereinafter "Yunessun") will host the event "Demon Slayer: Kimetsu no Yaiba × Yunessun — Hakone Onsen Tan: Rest at the Wisteria Flowers' Inn," featuring the world of the Demon Slayer anime — including the theatrical film Demon Slayer: Kimetsu no Yaiba — Infinity Castle Arc, Chapter 1: Akaza Returns, which surpassed 40 billion yen at the box office. The swimwear-friendly hot spring "Yunessun" will feature collaboration baths and a sauna themed on the "Wisteria Crest House" from the story, as well as a collaboration bath evoking the "Infinity Castle."
For those who want to immerse even further in the world of Demon Slayer: Kimetsu no Yaiba, the adjacent Hakone Hotel Kowakien will offer the collaboration room "Demon Slayer: Kimetsu no Yaiba Room" (one room per day, limited availability), decorated with iconic scenes from the anime and films.
Event Name: Demon Slayer: Kimetsu no Yaiba × Yunessun — Hakone Onsen Tan: Rest at the Wisteria Flowers' Inn
Period: Saturday, July 18 – Sunday, October 4, 2026
Content: Collaboration baths, collaboration sauna, collaboration tickets, collaboration drinks, collaboration merchandise, collaboration room, collaboration accommodation plans, and more
Special Site: https://www.yunessun.com/kimetsu2026
Subject to change or cancellation without notice. Collaboration plans may be fully booked. Cancellations will make rooms available again.
Okinawa Comes to Hakone — Hakone Kowakien Okinawa Haisai Festival
Inspired by ties with Kanucha Resort, a leading Okinawan resort, the Hakone Kowakien Okinawa Haisai Festival will be held across the Hakone Kowakien complex. Events will span the resort's hotels and ryokan with a cross-venue approach. Guests can enjoy Okinawan flavors and culture while surrounded by the natural scenery of Hakone.
365-Day Festival Plaza — Okinawa Culture Activities
The traditional carnival booth area (featuring games like shooting galleries and garapon lottery) will offer Okinawa-themed prizes. Limited-time Okinawan craft activities such as "Shisa Painting" and "Craft Drum-Making" will also be available. Alongside a panel exhibition on the environment surrounding coral reefs and an underwater photo exhibition featuring "Fish of Okinawa," the area is recommended for children's summer research projects as well as for families.
The daily stage events will feature staff dance and music performances incorporating Okinawan culture, as well as appearances by Eisa teams "桜風エイサー琉球風車 (Oufuu Eisa Ryukyu Fusha)" and "湘琉会 (Shouryuukai)" on an irregular schedule.
Okinawa Craft Activities
- Venue: Yunessun 3F, 365-Day Festival Plaza (free admission area)
- Period: Wednesday, July 1 – Monday, August 31, 2026
- Content: Shisa painting, craft drum-making experience, and more
- Participation fee: From ¥1,300
Coral Conservation Panel Exhibition & Fish of Okinawa Photo Exhibition
- Venue: Yunessun 3F, 365-Day Festival Plaza (free admission area)
- Period: Wednesday, July 1 – Monday, August 31, 2026
- Participation fee: Free
Stage Events at 365-Day Festival Plaza
- Venue: Yunessun 3F, 365-Day Festival Plaza (free admission area)
- Participation fee: Free
- Schedule: Published sequentially on the official website. Check the Yunessun official website for details.
Hakone to Okinawa Present Campaign
To celebrate the Hakone Kowakien Okinawa Haisai Festival, a prize campaign will be held. There are two entry courses: an SNS entry course with Yunessun admission tickets as prizes, and a grand prize course offering a pair of accommodation vouchers for Kanucha Resort or Hotel Gracery Naha — the only property in Okinawa among the company's group hotels.
SNS Entry Course (Yunessun / Lunch Vouchers)
- Entry Period: Wednesday, July 1 – Monday, August 31, 2026
- How to Enter:
- Take a photo at the photo spot on the 1st floor of Yunessun.
- Post the photo on Instagram with the hashtag #ユネッサンでハイサイ！
- Follow the accounts of 4 facilities: Hakone Kowakien Yunessun, Hakone Hotel Kowakien, Hakone Kowakien Ten-yu, and Hotel Gracery Naha.
Winners will be contacted via Instagram DM from the Yunessun Hakone official account (@yunessun_hakone). Please ensure your DM settings allow messages from this account.
Grand Prize Course (Pair Accommodation Vouchers)
- Entry Period: Wednesday, July 1 – Monday, August 31, 2026
- How to Enter:
- Book and stay via the Hakone Hotel Kowakien official website (https://www.hakone-hotelkowakien.jp/) or the Hakone Kowakien Ten-yu official website (https://www.ten-yu.com/).
- Target stay period: Wednesday, July 1 – Monday, August 31, 2026
- Fill out the entry form available at the front desk of each facility and place it in the entry box.
Winners will be notified directly.
Hakone Kowakien Staff Programs — Okami Experience & Bozappi's Cooldown Mission!
Okami Experience at Ten-yu (Hakone Kowakien Ten-yu)
The popular "Okami Experience" children's program returns to Ten-yu for summer 2026. Participants learn greetings, kimono dressing, and hospitality manners directly from the okami (inn mistress). The program cultivates children's curiosity through unique experiences and interaction with staff, making it well suited for "educational travel."
- Period: Wednesday, July 1 – Monday, August 31, 2026
- Participation fee: ¥3,000 per person (tax included)
- Reservation: https://x.gd/V3hmp
Bozappi's Cooldown Mission! at Yunessun (Okinawa Version)
The water spray program "Bozappi's Cooldown Mission!" — held for the first time last summer — returns in a new Okinawa version at Yunessun. Yunessun's official character "Hakoneko Bozappi" and staff share a fun, interactive time with guests. It's a uniquely Yunessun experience that brings staff and visitors together.
- Venue: Swimwear hot spring "Yunessun" — Gods of the Aegean Sea area
- Period: Saturday, July 18 – Sunday, September 6, 2026
- Hours:
- Weekdays: 10:00 AM – 6:00 PM (last entry 5:00 PM)
- Weekends and holidays: 9:00 AM – 7:00 PM (last entry 6:00 PM)
- Admission (Yunessun swimwear area):
- Adults (middle school age and above): from ¥2,500 (tax included)
- Children (age 3 and above): from ¥1,400 (tax included)
From August 8 (Sat) to 16 (Sun), a separate "time-slot ticket" may be required in addition to the regular admission ticket. Check the official website for details.
