Three Day-Use Onsen Around Oarai and Hitachinaka

The coast north of Mito has three day-use baths that make very different outings. Shiosai no Yu is the one to pair with Oarai's beach and seafood stops. Ajigaura Onsen Nozomi is the easiest of the three to reach by train and has five bookable private baths. Hitachinaka Onsen Kirari Bettei sits inland; come here for a longer bath-and-sauna break, not an ocean view.

Special-date prices and closures can override the usual schedule. Kirari Bettei does not admit preschool children. Nozomi's calendar can include exceptions to its usual Thursday closure.

Shiosai no Yu: a coastal bath after Oarai sightseeing

This is the coastal choice. The open-air bath looks out toward the Pacific, and the on-site restaurant serves seafood. If you have spent the day around Oarai Sun Beach, the aquarium or the market, it is a natural place to stop before heading back.

Oarai Sun Beach Onsen is a sodium-chloride strong-saline spring associated with fossil seawater. Natural spring water feeds the ocean-view outdoor baths and jet baths. The high-concentration carbonated bath is made by adding carbon dioxide. Spring water is identified for selected tubs; the other bath treatments differ.

The current price and daily hours are in the comparison table above. Since April 2026, the regular schedule has been year-round opening with occasional unscheduled closure days; older listings showing a fixed third-Thursday closure are outdated.

Oarai Station is about five minutes away by taxi, and the bathhouse has parking for around 120 cars. Without a car, include the taxi ride in your plan. Tattoos are not permitted anywhere in the facility.

Ajigaura Onsen Nozomi: strong-saline water and a genuinely useful private-bath option

Nozomi draws its own sodium-chloride spring from a well about 1,506 metres deep. It is a high-concentration, strongly saline spring. The baths include an indoor pool, several outdoor tubs, a hinoki bath set to about 43–44°C, a nano-mist sauna and a cold plunge. The hinoki bath's temperature is not the source temperature.

The comparison table above gives the regular admission and hours. Listed special dates around New Year, Golden Week and Obon cost ¥1,350. Thursday is the usual closing day, though the monthly calendar may show holiday openings or other changes.

All five private family baths use 100% free-flowing source water.

Admission is charged separately for each person. Children under three cannot use the shared baths but may use a private one. Guests with tattoos may also use a private bath; tattoos are not allowed in the shared bathing area.

Ajigaura Station on the Hitachinaka Seaside Railway is about an eight-minute walk away. A taxi from Katsuta Station takes around 15 minutes. Shampoo, conditioner, face wash, body soap and hair dryers are provided. Face towels rent for ¥150 and bath towels for ¥250.

If you need both towels, weekday admission plus rentals comes to ¥1,380.

Kirari Bettei: fields and a longer spa visit

Kirari Bettei is in Ichige, inland from the coast. Its outdoor baths look over fields toward Mito. The Simple Course costs ¥990 and includes a rental towel set; the ¥1,540 Relaxed Course adds indoor wear and a large towel. The Simple Course excludes the stone-spa area. Weekday and weekend prices are the same, with special rates possible on selected dates.

It opens at 8 a.m. and closes at 11 p.m., with last admission at 10 p.m. Maintenance closures are scheduled through the year. Only elementary-school-age children and older may enter, so families with preschoolers will need another option.

The spring is a sodium-bicarbonate/chloride spring. One outdoor bath uses filtered, recirculated spring water; a separate “Source View Bath” is free-flowing. There are also indoor baths, a sauna and an optional stone spa, making this a better fit for a longer visit than a quick coastal stop.

From Mito Station or Katsuta Station, take a bus to Tsukubadai and walk a few minutes—about three minutes from the Mito route and five from the Katsuta route. Drivers have access to a free 207-space car park.

Which one fits your day?

On an Oarai day, Shiosai no Yu keeps the bath, beach and seafood in the same area. Nozomi fits a train trip along the seaside railway and offers a private bathing option. From a Mito or Katsuta base, Kirari Bettei is an easy choice for a longer bathhouse visit.

Tattoo rules differ: Shiosai no Yu refuses entry; Nozomi allows tattooed guests in private baths only; Kirari Bettei does not accept tattoo cover stickers. Kirari Bettei also excludes preschoolers. Nozomi's private bath is the clearest option for a family with a child under three, while Shiosai's shared-bath arrangements for very young children should be confirmed before visiting.

Sources

- [Shiosai no Yu: fees and hours](https://siosai.jp/) - [Shiosai no Yu: bath guide](https://siosai.jp/contents/01spa.html) - [Ibaraki tourism: Shiosai no Yu access listing](https://www.ibarakiguide.jp/spot.php?code=923&mode=detail) - [Ajigaura Onsen Nozomi: visitor information](https://www.ajigauraonsen.jp/info/) - [Nozomi: spring and baths](https://www.ajigauraonsen.jp/spring/) - [Nozomi: private baths](https://www.ajigauraonsen.jp/private-spa/) - [Nozomi: access](https://www.ajigauraonsen.jp/access/) - [Hitachinaka Onsen Kirari Bettei: fees and hours](https://www.yurakirari.com/hitachinaka/fee/) - [Kirari Bettei: outdoor baths](https://www.yurakirari.com/hitachinaka/spa/) - [Kirari Bettei: access](https://www.yurakirari.com/hitachinaka/access/)

Checked: 27 September 2026. Special-day rates, closures and transport can change; confirm before travelling.