Shiohama no Yu Shikoku Kenkomura: Hot Spring Guide

This large bathing complex stands on reclaimed land in Utazu, at the foot of the Great Seto Bridge. Open 24 hours a day, it covers baths and saunas, meals, popular theatre and even a nap all within one building. The Shikoku Aquarium is about a seven-minute walk away, which makes it easy to build a day around both. Its gentle alkaline water is a local favorite.

What the Baths and Saunas Offer

The star of the bathing area is the open-air bath "Udon Prefecture Kamaage no Yu." The official site describes it as a "milky white, alkaline" bath whose "water quality is soft and mild." The posted benefits are acne, heat rash, eczema, rough skin, sensitivity to cold, stiff shoulders, lower back pain, fatigue recovery, neuralgia, rheumatism, chilblains, chapped skin, cracked skin, hemorrhoids, bruises, sprains, and sensitivity to cold before and after childbirth. No formal spring classification or source temperature is published, so this is a different kind of place from a hot spring town where you study the mineral analysis and savor the water. Rather than expecting a free-flowing wild bath, the right way to approach it is as a well-equipped bathing facility.

The indoor baths include an electric bath, a bubble bath, a jet bath and a cold-water bath. Together with the open-air bath the variety of tubs is wide, and space is also set aside for cooling off in the outside air.

The saunas are the part that has been reinforced in recent years. In December 2023 a loyly sauna was newly installed in the women's bathing area, where you can pour water yourself onto the electric sauna heater. It has two tiers of wooden benches and holds eight people. Aufguss sessions by female staff are held twice daily, at 18:30 and 20:30. The men's-only sauna has been converted to auto-loyly, with water running onto the sauna stones at fixed intervals. Every Saturday there is "MUSIC Loyly," where the background music changes with each netsuwaza (heat-wave) performer, and on Sundays the men's side adds extra sessions at 8:00, 11:00 and 15:30.

Enjoying the Seasons

In summer feel the sea breeze near the Great Seto Bridge, and in winter warm up with a long, slow soak. Whatever the season, the quiet late-night and early-morning hours are ideal for enjoying the baths.

Practical Information

• Character of the water: the official site describes it as a "milky white alkaline bath." The formal spring classification, source temperature, and whether it is free-flowing or recirculated are not published
• Bathing hours: 6:00 in the morning to 1:00 after midnight. Bathing is not possible from 1:00 to 6:00 because the bathing area is cleaned (the building itself is open 24 hours)
• Six-hour plan: adults 980 yen on weekdays / 1,100 yen on weekends, holidays and designated days; children (age 3 to elementary school) 600 yen. A student discount (junior high, high school, university and vocational students) is 880 yen on all days. Available 5:00 in the morning to 2:00 after midnight, last reception 23:00
• Leisurely free plan: adults 2,200 yen on weekdays / 2,400 yen on weekends, holidays and designated days; children 1,300 yen. You may stay from 5:00 in the morning until 2:00 after midnight
• Morning bath plan: 6:00 to 9:30 (last reception 9:00), adults 650 yen on weekdays / 700 yen on weekends and holidays, children 450 yen
• Late-night bath plan: 23:00 to 2:00 (last reception 0:30), adults 650 yen on weekdays / 700 yen on weekends and holidays, children 450 yen. The bathing area may be used until 1:00
• Late-night entry plan: 2:00 after midnight to 10:00 in the morning (last reception 4:00), adults 3,000 yen on weekdays / 3,200 yen on weekends and holidays, children 2,000 yen. The bathing area may be used from 6:00
• Late-night stay charge: if you remain in the building from 2:00 to 10:00 on a free plan, an extra 1,500 yen is added
• Closed days: the Marugame City Tourism Association lists the second Thursday as the regular closing day. According to the official site's 2026 notice, the whole facility is closed on January 8, May 13 and 14, and September 9 and 10, while on the other machine-maintenance days (February 12, March 12, April 7, June 11, August 20, October 8, November 12, December 10) it closes temporarily from 9:30 to 17:00 and reopens as usual from 17:00
• Designated days (days charged at the weekend and holiday rate): in 2026 these are January 1 to 4, May 1 to 6, August 8 to 16, September 19 to 23, and December 26 to 31
• Payment: cash, credit cards and cashless payments are accepted. However, transit-card electronic money cannot be used
• Provided amenities: shampoo, conditioner, body soap, hair dryers and cotton swabs. Face wash that also removes makeup is at the washstand in front of the women's bath entrance, and all-in-one lotion (men's) / all-in-one cream (women's) is in the powder room
• Rentals and sales: house wear 350 yen, towel set 300 yen, bath towel 250 yen, face towel 200 yen. The shop sells items such as a toothbrush 70 yen, razor 165 yen, nylon towel 275 yen, comb 165 yen and a Shikoku Kenkomura towel 220 yen
• With children: in line with the Ministry of Health, Labour and Welfare's management guidelines, children aged 7 and over or 120 cm and taller use the bathing area matching their gender. Children not yet out of diapers must use the baby bath placed at the entrance of either bathing area
• Parking: 200 spaces
• Access: about a 20-minute walk from JR Utazu Station, with a free shuttle bus from the station. By car it is about 5 minutes from Sakaide-kita IC on the Seto-Chuo Expressway (Sakaide-kita IC can only be used from the Okayama direction), about 10 minutes from Sakaide IC on the Takamatsu Expressway, about 60 minutes from Naruto IC, about 50 minutes from Mima IC on the Tokushima Expressway, and about 60 minutes from Niihama IC on the Matsuyama Expressway
• Coupon tickets: electronic free-plan coupon books are 10,500 yen for five and 20,000 yen for ten. Electronic six-hour-plan coupon books are 8,800 yen for ten. They are sold at the information counter's merchandise section and used with a LINE membership or membership card
• On site: popular theatre (reserved seats cost extra on top of admission; floor chairs and raised chairs for the evening performance are 220 yen, for example), a cafe restaurant, a rest room with 10,000 manga volumes, and lodging in capsule rooms or Japanese-style rooms
• Nearby: about a 7-minute walk to the Shikoku Aquarium
• Address: 6-10 Hama Ichibancho, Utazu-cho, Ayauta-gun, Kagawa Prefecture (0877-49-2600)

How Not to Lose Out When Choosing a Plan

The easiest thing to get wrong here is the fee plan. The six-hour plan clearly states that "once your stay reaches six hours, or once 2:00 after midnight has passed, the plan automatically switches and an additional charge is applied." In other words, if you carelessly linger, you will end up paying the difference. Conversely, anyone who wants to watch the daytime popular-theatre performance cannot get in on the six-hour plan, so you need to choose the free plan from the start (the evening performance can be watched on the six-hour plan, with no extra charge on weekdays and plus 300 yen on weekends and holidays).

The other pitfall is the designated days. During Golden Week, the Obon period and the New Year holidays, even weekdays are charged at the weekend and holiday rate. The difference is 200 yen on the free plan and 120 yen on the six-hour plan, but for a family it adds up. If your itinerary falls over a long holiday, checking the list of designated days above in advance will put your mind at ease.

A Quick Tip

With sleeping rooms and rest spaces available, it suits late arrivals and early departures alike, so use it as a rest stop on a long trip. Since fees vary by length of stay, choosing a plan that matches your time on site is the better value.

📚 Sources

The fee plans (six-hour, free, morning bath, late-night bath, late-night entry), the late-night stay charge, payment methods, rental items and shop amenities, coupon books, the 2026 designated days and closed days and days with changed hours, and access by car and train were confirmed from the fee tables and information images posted on the guide page of the official Shiohama no Yu Shikoku Kenkomura site. The layout of the bathing area, the description and benefits of the water, the provided amenities, the mixed-bathing age limit and the handling of baby baths, and the bathing hours come from the bath page; the date the loyly sauna was installed and the event times come from the sauna page; and the distance to the Shikoku Aquarium comes from the facility guide page. The 200 parking spaces and the note that it is "closed on the second Thursday as a rule" were confirmed from the Marugame City Tourism Association's facility information. Details are subject to change, so please check official sources before visiting.

Practical Information for Your Visit

• Nature of the water: The official website describes it as milky-white alkaline water. The formal spring quality name, the source temperature and whether the water is free-flowing or recirculated are not published
• Bathing hours: 6:00 in the morning to 1:00 at night. Bathing is not possible from 1:00 to 6:00 while the bathrooms are cleaned (the building itself is open 24 hours)
• 6-hour plan: Adults 980 yen on weekdays and 1,100 yen on weekends, public holidays and designated days; children (aged 3 to elementary school age) 600 yen. The student rate (junior and senior high school, university and vocational school students) is 880 yen on any day. Available from 5:00 in the morning to 2:00 the following night, with last admission at 23:00
• Relaxed free plan: Adults 2,200 yen on weekdays and 2,400 yen on weekends, public holidays and designated days; children 1,300 yen. You can stay from 5:00 in the morning until 2:00 the following night
• Morning bath plan: 6:00-9:30 (last admission 9:00), adults 650 yen on weekdays and 700 yen on weekends and public holidays, children 450 yen
• Late-night bath plan: 23:00-2:00 (last admission 0:30), adults 650 yen on weekdays and 700 yen on weekends and public holidays, children 450 yen. The bathrooms can be used until 1:00
• Late-night entry plan: 2:00 to 10:00 in the morning (last admission 4:00), adults 3,000 yen on weekdays and 3,200 yen on weekends and public holidays, children 2,000 yen. The bathrooms can be used from 6:00
• Late-night stay charge: If you remain in the building between 2:00 and 10:00 on a free plan, there is an additional 1,500 yen
• Closing days: The Marugame City Tourism Association guide says it is generally closed on the second Thursday of the month. According to the official website's guidance for 2026, the whole facility is closed on January 8, May 13 and 14, and September 9 and 10, while on the other machinery adjustment days (February 12, March 12, April 7, June 11, August 20, October 8, November 12 and December 10) it closes temporarily from 9:30 to 17:00 and operates normally from 17:00
• Designated days (days charged at the weekend and public holiday rate): In 2026 these are January 1-4, May 1-6, August 8-16, September 19-23 and December 26-31
• Payment: As well as cash, credit cards and cashless payment can be used. Transport IC e-money, however, is not accepted
• Amenities provided: Shampoo, conditioner, body soap, hairdryers and cotton buds. At the washbasin in front of the entrance to the women's bathroom there is a combined face wash and makeup remover, and in the powder room there is all-in-one lotion (men) and all-in-one cream (women)
• Rental and sales: Indoor wear 350 yen, towel set 300 yen, bath towel 250 yen, face towel 200 yen. The shop sells toothbrushes at 70 yen, razors at 165 yen, nylon washcloths at 275 yen, combs at 165 yen and Shikoku Kenkomura towels at 220 yen, among other things
• With children: In line with the management guidelines of the Ministry of Health, Labour and Welfare, children aged 7 and over or 120 cm or taller use the bathroom for their own sex. Children who are not yet out of diapers must use the baby baths placed at the entrance to both the men's and women's bathrooms
• Parking: 200 spaces
• Access: About a 20-minute walk from JR Utazu Station. There is a free shuttle bus from the station. By car it is about 5 minutes from the Sakaide-kita Interchange on the Seto-Chuo Expressway (Sakaide-kita Interchange can only be used from the Okayama direction), about 10 minutes from the Sakaide Interchange on the Takamatsu Expressway, about 60 minutes from the Naruto Interchange, about 50 minutes from the Mima Interchange on the Tokushima Expressway and about 60 minutes from the Niihama Interchange on the Matsuyama Expressway
• Multi-ticket books: An electronic free-plan ticket book costs 10,500 yen for 5 tickets or 20,000 yen for 10. An electronic 6-hour-plan ticket book costs 8,800 yen for 10 tickets. They can be bought from the sales counter at the information desk and are used with a LINE membership or a membership card
• Attached facilities: Popular theater (reserved seats cost extra on top of the admission fee, with floor chairs and raised chairs at the evening performance costing 220 yen and so on), a cafe restaurant, a rest room where you can read 10,000 manga volumes, and accommodation in capsule rooms or Japanese-style rooms
• Nearby: About a 7-minute walk to the Shikoku Aquarium
• Address: 6-10 Hama Ichibancho, Utazu Town, Ayauta District, Kagawa Prefecture (0877-49-2600)

How to Choose a Plan Without Losing Out

The easiest thing to get wrong at this facility is the price plan. It states clearly that with the 6-hour plan, once you have stayed 6 hours, or once it passes 2:00, the plan automatically switches over and an extra charge is added. In other words, linger by accident and you end up paying the difference. Conversely, anyone who wants to see the afternoon performance of the popular theater cannot get in on the 6-hour plan, so they need to choose the free plan from the outset (the evening performance can be seen on the 6-hour plan too, with no extra charge on weekdays and 300 yen more on weekends and public holidays).

The other pitfall is the designated days. During Golden Week, Obon and the New Year period, weekend and public holiday rates apply even on weekdays. The difference is 200 yen on the free plan and 120 yen on the 6-hour plan, but with a family that adds up. If your trip falls over a long weekend, it is reassuring to check the list of designated days above first.

Information Sources

The price plans (6-hour, free, morning bath, late-night bath and late-night entry), the late-night stay charge, the payment methods, the rental items and shop amenities, the multi-ticket books, and the designated days, closing days and days with changed hours for 2026, as well as access by car and by train, were confirmed from the price tables and information images posted on the visitor guide page of the official Shiohama no Yu Shikoku Kenkomura website. The composition of the bathrooms, the description of the water and its benefits, the amenities provided, the age limit for mixed bathing and the arrangements for baby baths, and the bathing hours come from the bath page; the date the loyly sauna was added and the times of its events come from the sauna page; and the distance to the Shikoku Aquarium comes from the facility guide page. The 200 parking spaces and the statement that it is generally closed on the second Thursday were confirmed in the facility information of the Marugame City Tourism Association. Details are subject to change, so please check official information before you set out.