Hakone Kowakien Yunessun

What to expect

Yunessun is a hot spring theme park, not a quiet onsen. It opened in 2001 at Kowakudani, on Route 1 above Hakone-Yumoto, and is run by Fujita Kanko, the company behind the Hakone Kowakien hotels. It had its biggest renovation in 2023 and turned 25 on January 1, 2026.

There are two zones, and they work very differently:

• Yunessun is the swimsuit zone. Families, couples and groups of friends move between indoor pools, outdoor baths and slides, all in swimwear. This is where the novelty baths are: a wine bath, a coffee bath and a sake bath. The wine bath was rebuilt as a winery-style room with vines and barrels and reopened on September 18, 2026.
• Mori no Yu is a conventional Japanese onsen. Men and women bathe separately and nude, in an indoor bath, an outdoor bath, a Shigaraki pottery bath, a reclining bath and a sauna. Its lobby and rest areas were redone in March 2025. It also has private baths for families, couples and wheelchair users.

Both zones use water from Yunessun’s own source, which the park describes as Kowakudani Onsen, a sodium chloride spring. The park does not publish pool temperatures.

The pools

In the Yunessun zone, the outdoor “mountain” and “sky” areas hold the larger soaks. The panoramic outdoor bath is about 40 m (130 ft) long and looks across the Hakone hills. Great Fall Onsen has a heavy cascade you can stand under, Rock Cave Onsen has small aquarium windows, and there is a Finnish bath for sweating it out. Rocky’s Splash opened on March 25, 2025: two slides, one spinning and one through rings of light, filled with warm water so they run in winter. Riders must be at least 105 cm tall.

Indoors you find the themed baths, a Dr. Fish foot bath and two children’s pools, Pony Lagoon (30 cm deep with a 1 m slide) and Bozappy River.

The pours are what most people come for. On weekdays, staff add coffee at 12:30 and 14:00 and wine at 12:40 and 14:10. On weekends and holidays, coffee goes in at 12:00 and 15:00 and wine at 12:15 and 15:15.

Prices and booking

Yunessun uses variable pricing on an A, B and C calendar; A broadly matches weekdays and B and C weekends, holidays and peak dates. Standard 2026 rates:

• Passport (both zones): adults ¥3,500 / ¥3,700 / ¥4,000; children ¥1,800 / ¥1,900 / ¥2,000.
• Yunessun only: adults ¥2,500 / ¥2,800 / ¥3,000; children ¥1,400 / ¥1,500 / ¥1,700.
• Mori no Yu only: adults ¥1,500 / ¥1,700 / ¥1,800; children ¥1,000 / ¥1,100 / ¥1,200.

Adults are junior high school age and up; children are 3 to primary school age; under 3 is free. People 65 and over and disability certificate holders (plus up to two companions) get lower rates with ID. Tickets bought online in advance are cheaper than these gate prices.

Rentals: bath towel ¥250, face towel ¥150, swimsuits from ¥1,200 for adults, ¥700 for children and ¥800 for babies. You can bring your own. There are about 4,000 lockers, most of them free. Inside the park you pay by card, phone or watch; cash works only in vending machines.

Hours: Yunessun opens 10:00-18:00 on weekdays and 9:00-19:00 on weekends and holidays, with last entry an hour before closing. Mori no Yu opens 11:00-20:00 every day, last entry 19:30.

Rules and etiquette

• Tattoos: generally refused, including stickers. In the swimsuit zone they are allowed if covered, for example with a rented rash guard. In Mori no Yu, a tattoo must be fully hidden by two of the park’s paid cover seals; if not, book a private bath.
• Children: under junior high school age cannot enter without an adult. By local ordinance, children 7 and over must use the changing rooms, baths and toilets of their own sex; there is also a shared “Everyone’s Changing Room” for lockers. Babies not yet toilet trained need a swim diaper under their swimsuit.
• Food: no outside food or drink, except baby food and allergy-safe meals.
• Gear: no snorkels, fins, water guns or balls, and floats no bigger than 100 cm across.
• Phones: keep them in a waterproof case, which you can buy inside.
• Mori no Yu: standard onsen manners apply. Wash at the taps before you get in, keep towels out of the water, and no swimsuits.

Getting there

The address is 1297 Ninotaira, Hakone. The Kowakien bus stop is just across the road.

• From Shinjuku: Odakyu Romancecar to Hakone-Yumoto, about 90 minutes, then a Hakone Tozan Bus or Izuhakone Bus, about 20 minutes.
• From Tokyo Station: Shinkansen Kodama to Odawara, about 35 minutes, then the bus, about 40 minutes.
• By car from Tokyo: Odawara-Atsugi Road from Atsugi IC to Hakoneguchi IC, about 30 minutes, then Route 1 uphill, about 30 minutes. From Gotemba IC, Route 138 to the Miyanoshita junction and right, about 40 minutes.

There are two car parks, with 180 and 330 spaces, open 8:00-22:00. Parking is ¥1,300 a day on weekdays and ¥1,600 on weekends, holidays and peak dates, with the first two hours free. Sleeping in your car is not allowed.

When to go

The B and C rates cover weekends, holidays and peak periods, which are also the busiest days. A weekday on the A rate is cheaper. Arrive at opening to get lockers and outdoor baths before the crowds, and plan your afternoon around the wine and coffee pours.

Where to stay nearby

The Hakone Kowakien hotels are next door, and guests at four designated Kowakien properties get unlimited Yunessun access during their stay. The park’s site lists Hakone Kowakien Ten-yu, Miyama Furin and Mikawaya among its partner hotels. Hakone-Yumoto, 20 minutes down the hill by bus, has the widest choice of ryokan and hotels and is the main rail gateway.

Safety notes

• Heat: Moving between hot baths and slides for hours dehydrates you. Drink water and take breaks.
• Access: Wheelchairs are allowed, but the park says it is not fully barrier-free and has steps between levels. Call 0460-82-4126 for details.
• Slides: Follow the height limit and staff instructions; the outdoor slide surfaces are wet all year.
• Changes: The park says event times and content can change without notice. Check the official site on the day.