Reference price as of September 12, 2026 (stay date 2026-10-03). Please check the booking site for actual rates.
Check rates & availability
Opens the booking site in a new tab.
This site uses affiliate links; we may earn a commission on bookings.
forumWhat families say
Rakuten Travel rating 4.8 out of 5 (369 reviews). Guests praise the natural onsen Ningyo no Yu, with Mount Fuji visible across the sea, the footbath looking out over Tokyo Bay, and the seafood cuisine made with a sugatamori platter of local fish served whole and home-grown vegetables raised without agricultural chemicals. The adjacent drive-in campground with its BBQ house and the detached Ningyo no Yakata with its own open-air bath are well received too.
Kids Facilities
The detached Ningyo no Yakata
The detached Ningyo no Yakata
A detached building with its own open-air bath, made up of a 45-square-meter Japanese-style tatami room with a toilet. It sleeps 2 to 4 guests and has won an award on the TV program TV Champion. Because it has a private open-air bath, the family can bathe together without using the separate men's and women's communal baths. Accommodation plans for it include child rates.
- •It can be used by 2 to 4 guests.
Categories
Overview
Kaikouzu is a ryokan standing on the coast in Tateyama, Chiba, with views over Tokyo Bay from the guest rooms and the terrace. The spring water at the natural onsen Ningyo no Yu is a sodium chloride strong-salt spring, and its separate men's and women's bathrooms can be used from check-in until 9 a.m. the next morning. Guest rooms range from the detached Ningyo no Yakata with its own open-air bath, to Japanese-style tatami rooms and Japanese-Western rooms with a bath in the room, to renovated Japanese-style tatami rooms whose guests use the communal bath, and every accommodation plan has child rates. The ryokan is close to the beach, and it also has a footbath on the terrace and a coin laundry.
Rooms
There are four room types. The detached Ningyo no Yakata, which has its own open-air bath, is 45 square meters with a toilet, has won an award on the TV program TV Champion, and sleeps 2 to 4 guests. There are also a 10.5-tatami Japanese-style tatami room and a 12.5-tatami Japanese-Western room, both with a bath and toilet in the room; that bath is not onsen water but micro fine bubble water. The Japanese-Western room has 2 single beds, and from 3 guests onward futon bedding is laid out. The renovated 8-tatami Japanese-style tatami room has a toilet, and guests use the communal bath. This room is in the old building rather than the main building, which was built in Reiwa 4 (2022), and it is reached by steep stairs. Accommodation plans for every room type include child rates. There is a microwave for guests to share on the property, and the guest rooms have a refrigerator and an electric hot-water kettle.
Dining
Breakfast and dinner are both served in the banquet hall and dining room, with dinner from 6 p.m. and breakfast from 8 a.m. The meals center on kaiseki course cuisine made with local seafood, and a sugatamori platter of sashimi served with the whole fish comes as standard. The vegetables are organically grown without agricultural chemicals, and the ryokan raises its own tomatoes, eggplant, daikon radish, potatoes, peanuts, cucumbers and shiso leaves.
Baths and Onsen
The natural onsen Ningyo no Yu is a sodium chloride strong-salt spring. The bathrooms are separate for men and women, and staying guests can bathe from the day they check in until 9 a.m. the next morning. The baths are unavailable from 9 a.m. to 11 a.m. for cleaning. The detached Ningyo no Yakata has its own open-air bath, so you can bathe in your room's bath rather than using the communal bath.
Family-Friendly Features
Accommodation plans for every room type include child rates, which makes staying as a family straightforward. The detached Ningyo no Yakata comes with its own open-air bath, so it is the room to choose if you want to bathe with a small child without worrying about other guests. The renovated Japanese-style tatami room, on the other hand, is in the old building rather than the main building and is reached by steep stairs, so take care when moving a stroller or when small children go up and down. After swimming in the sea, you cannot enter the building still covered in sand or in wet clothes; brush the sand off and change into dry clothes before coming inside.
Access
The address is 85-1 Oga, Tateyama, Chiba. By car, allow about 90 minutes from Tokyo via the Tokyo Bay Aqua-Line. Going via the Tateyama Expressway, it is about 90 minutes from Tokyo to the Kisarazu-minami Interchange, then about another 70 minutes along Route 127. By train, take a JR bus for 15 minutes from Tateyama Station on the JR Uchibo Line and get off at the Kaikouzu-mae stop, or take a taxi for 10 minutes. There is parking for 50 cars, free of charge and on a first-come, first-served basis. A 7-Eleven is about a 2-minute walk (about 150 meters) away, the ODOYA Tateyama Kaigan supermarket is 5 to 6 minutes by car, and Tateyama Station is about 10 minutes by car.
Access & Information
| location_onAddress | 85-1 Oga, Tateyama, Chiba 294-0031 |
|---|---|
| directions_carAccess | From Tateyama Station on the JR Uchibo Line, about 15 minutes by JR bus, getting off at the Kaikouzu-mae stop, or about 10 minutes by taxi. |
| trainNearest station | Tateyama Station |
| local_parkingParking | Free parking for 20 cars, on a first-come, first-served basis. |
| callPhone | +81-470-23-1212 |
| paymentsCards | VISA, American Express, UC |
| languageOfficial site | https://www.kaikouzu.com/open_in_new |
Map
The map is provided by Google Maps. Loading it sends your IP address to Google, which may set cookies. It is loaded only when you choose to.
Reference price as of September 12, 2026 (stay date 2026-10-03). Please check the booking site for actual rates.
Check rates & availability
Opens the booking site in a new tab.
Frequently Asked Questions
What ages is Kaikouzu best suited to?
expand_more
It has facilities that work especially well for babies and toddlers (ages 0 to 2) and children aged 3 and over. There is no age limit, and families with children of any age can stay.
Is there parking at Kaikouzu?
expand_more
Parking: Free parking for 20 cars, on a first-come, first-served basis.
How do you get to Kaikouzu?
expand_more
From Tateyama Station on the JR Uchibo Line, about 15 minutes by JR bus, getting off at the Kaikouzu-mae stop, or about 10 minutes by taxi.
Up to what age are child rates available?
expand_more
Children aged 0 to 12 can stay, and every accommodation plan has child rates. There are several room types, from Ningyo no Yakata to the Japanese-style tatami and Japanese-Western rooms and the renovated Japanese-style tatami room, and child rates apply in all of them.
Related hotels
Family-friendly hotels in Minami-Boso
Hotels with Private Cottage / Villa in Minami-Boso
Collections featuring this hotel
Autumn Farms and Harvest
Hotels with farm activities and animal encounters, plus the areas that make the best base for fruit picking and harvest days, from Hokkaido to Kyushu
Autumn Cottages and Glamping
No one else to worry about, at your children's own pace. Areas with self-catering villas, cottages, and glamping, from north to south
Autumn Long Weekends With Kids
Skip the crowds and traffic with hotels where short travel and on-site or nearby fun are enough. Four ways to spend it: highlands, hot springs, the sea, or a large resort
Find other hotels
Find other hotels
Information on this page was compiled by directly consulting Official website, Rakuten Travel, Jalan (last verified: August 2026). Prices, availability and seasonal operations change. Please check each booking site for the latest information.
We take care to keep information accurate, but always confirm the latest details on the hotel's official site and booking sites before you book or visit.
For the people who run this property: corrections and updates go through For Hotels & Partners, and the "Listed on Kids Stay" badge for your website is on Listing badge. Both are free.