Onga is a ryokan in Kusatsu Onsen, Gunma, surrounded by forest with a view toward Mount Shirane. It calls itself a new style of inn where you spend your stay with your pet: you sleep in the same room, eat together in a private dining room, and let your dog run in a 400-tsubo dog run. Before you book, three things matter: the pet rules are strict (dogs up to 15 kg, at least one year old, vaccinated), payment is in cash, and the kitchen does not change meals for allergies.
Onga at a glance
| Item | Official information |
|---|---|
| Address | 740-3 Kusatsu, Kusatsu-machi, Agatsuma-gun, Gunma |
| Phone | +81-279-88-1212 |
| Rooms | 12 Japanese-style rooms |
| Check-in / out | 15:00 / 10:00 |
| Pets | Dogs up to 15 kg; 2,750 yen per pet per night |
| Baths | Free-flowing Kusatsu hot spring: large bath, paid private open-air bath, paid pet bath |
| Meals | Dinner and breakfast in a private dining room, pets welcome |
| Prices | From 19,800 yen per person, two meals, service and tax included |
| Payment | Cash |
| Parking | Free |
From the official site and booking page, read October 14, 2026.
Bringing your pet to Onga
Pets are the point of this inn, and the rules come first. The official site lists nine promises for staying. The table below keeps the ones that the site and the booking page agree on.
| Rule | What the official pages say |
|---|---|
| Age | At least one year old |
| Size | Dogs up to 15 kg |
| Lifestyle | Kept fully indoors at home, healthy |
| Vaccines | Rabies and other vaccinations done |
| Manners | House-trained and not prone to barking |
| Season | Not in heat |
| Fee | 2,750 yen per pet per night, tax included |
What happens if my dog has an accident or barks?
If your pet soils or damages the room or fittings, the inn may charge cleaning or repair costs later, and after an accident inside, you carry your pet when moving through the building. If barking disturbs other guests, the site says your dog may be asked to sleep in your car. The site also says you may be asked to show a vaccination certificate from within the past year, so bring it.
How many pets per room, and are cats allowed?
Here the official pages differ: the website and the booking page give different limits on pets per room, and they read differently on cats. Confirm both with the inn before you book. For pets other than dogs and cats, the site asks you to get in touch first.
What should I pack for my dog?
The site asks you to bring food, a leash, one pet sheet and a favorite toy. The inn provides a cage of about 60 by 90 cm and a pet toilet with sheets in the room. Outside, there is the dog run and a walking path through the woods. For how pet fees compare across Japan, see our guide to hotel pet fees.
Rooms at Onga
The inn has 12 Japanese-style rooms. The booking page lists a 10-mat tatami room with a living space of about 8 mats (51.8 square meters), a Japanese-Western room with Simmons twin beds, 8 mats of tatami and a living space of about 4 mats (also 51.8 square meters), and an 8-mat room of 25.9 square meters. Every room has a toilet with a bidet seat, a sink, a TV and air conditioning. Amenities include yukata, towels, shampoo, conditioner, a toothbrush, a hair dryer and down futons.
The baths at Onga
Kusatsu’s spring water runs straight from the source into the baths. The official site gives the spring as an acidic, sulfur-bearing water. There are three kinds of bath.
When is the large bath open?
The large bath is for people only; pets cannot enter. The booking page gives two different hours for it, so ask the inn which applies on your dates.
Is there a private bath?
Yes, an open-air private bath, booked after check-in for 45 minutes at an extra charge. Pets cannot use it. The figures on the site and the booking page differ, so confirm the price at the front desk.
Can I bathe with my dog?
Not in the hot spring, but there is a pet bath you can use together, with dog shampoo and a dryer, for 45 minutes at an extra charge. The site notes it is not hot-spring water.
Can I bathe with a tattoo?
The official pages do not mention tattoos. Ask the inn before you book.
Meals at Onga
What are dinner and breakfast like?
Both meals are served in a private dining room, so your pet can stay with you. The standard plan’s dinner is a Japanese course built around a seasonal hot pot, such as beef shabu-shabu or yosenabe; one plan upgrades the main dish to A4-grade Japanese black beef from Gunma. Extra dishes include scallop grilled with crab miso and horse sashimi. The official pages do not describe breakfast or give meal times.
Can the inn handle allergies or a special diet?
No. The booking page says the inn has one cook and no longer accepts requests to change meals, including for allergies, and that it cannot take responsibility for allergic reactions. If you have a serious allergy or a strict diet, contact the inn before you book.
Prices, children, cancellation and payment at Onga
How much does a stay cost?
Per person per night with two meals, the booking page lists the standard plan from 19,800 yen, the beef shabu-shabu plan from 22,000 yen, and a New Year plan (December 29 to January 3) from 33,000 yen. These include service charge and consumption tax. Add the pet fee of 2,750 yen per pet per night. The page says the official site has its lowest rates. Kusatsu town charges a bathing tax of 150 yen per person per night when the basic rate is over 6,000 yen; children of elementary school age and younger are exempt. The inn does not say whether its prices include it. See our onsen bathing tax guide.
What do children cost?
The booking page has four child categories, from elementary school pupils to children aged 3 to 5 without meals or bedding, but it does not list their prices. You see the price when you enter your party on the booking page.
What is the cancellation policy?
For 1 to 9 guests in up to two rooms: 20 percent from 7 days before, 40 percent from 3 days before, 70 percent the day before, 90 percent on the day and 100 percent for a no-show. Groups of 10 or more, or three rooms or more, pay from 14 days before. Over New Year (December 30 to January 3), Golden Week (May 1 to 5) and Obon (August 12 to 15), fees start 30 days before. Extra dishes are also charged. See our hotel cancellation guide.
How do I pay?
The booking page says payment is in cash. Plan to bring enough yen for the room, the pet fee and any extras.
Getting to Onga in Kusatsu Onsen
The site’s access map shows two train routes: the limited express Kusatsu to Naganohara-Kusatsuguchi Station, then a JR bus to Kusatsu; or the Shinkansen to Karuizawa, then a bus to Kusatsu. The official pages do not give the distance from the Kusatsu bus terminal to the inn or mention a pickup, so ask the inn how to reach it from the terminal. By car, the map shows the Kan-etsu Expressway to Shibukawa-Ikaho, then national routes to Kusatsu, and parking is free. For the trip from Tokyo, see our Kusatsu Onsen from Tokyo guide.
What foreign guests should know before staying at Onga
- There is no English website; the site and the booking page are in Japanese, and booking requires registering an account.
- Bring your pet’s vaccination certificate, food, leash and a toy.
- Payment is in cash, so carry enough yen.
- Meals cannot be changed for allergies; ask before you book if that matters.
- Confirm the per-room pet limit and the bath hours with the inn, since the official pages differ.
Frequently asked questions
How big can my dog be at Onga?
How much is the pet fee at Onga?
Can I pay by credit card at Onga?
Can Onga change my meals for a food allergy?
What time is check-in at Onga?
Bottom line (2026): Onga is a quiet Kusatsu Onsen ryokan made for staying with your dog: shared room, private dining room, dog run and a pet bath, with free-flowing hot spring for you. Check the pet rules, bring cash, and confirm the pet limit and bath hours with the inn.
Sources
Every fact on this page is from Onga’s official pages: home (Japanese), rooms and facilities, baths, meals, pet rules and access, the official booking page and its cancellation page, and Kusatsu town’s bathing tax page. All were read on October 14, 2026. Prices and rules change; check the official site before you book.
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