Kotohiki Kairo in Kagawa: Is the Sauna Lineup Worth a Detour?
Kotohiki Kairo’s 11 saunas are split between gendered sides that rotate by date. Check the odd/even lineup; adult entry is ¥950 weekdays and ¥1,100 weekends.
Kotohiki Kairo, in Kanonji on Kagawa’s western coast, pairs a natural hot spring with a large outdoor sauna area facing Ariake Beach. Its headline count—11 saunas and seven cold baths—covers both the men’s and women’s bathing areas. On a normal visit you use one side, and the sides switch by calendar date. Check the day’s lineup before planning around a particular room.
The date changes what you can use
The sauna total is spread across two bathing zones. The assigned side changes on odd- and even-numbered dates, so a standard ticket does not let you roam between the two areas and complete all 11 in one visit. The official facility guide lists six saunas on one side and five on the other.
That matters if a particular room is your reason for going. The Setouchi Lemon sauna is assigned to the men’s area on odd dates and the women’s area on even dates. Ariake Sauna, which faces west toward the sea and is positioned for sunset views, follows the reverse rotation. Check the current chart against both your visit date and the bath you will use.
What the lineup is like
The rooms have distinct formats rather than being one standard sauna repeated under different names. Setouchi Lemon is listed at 85°C with self-poured löyly. Ariake Sauna is listed at 95°C and has a west-facing view; other options include a Japanese-style reclining Kama Sauna, a ship-shaped room, a sauna car and tent saunas. The official guide also lists seven cold baths, including seawater and spring-water options.
The seawater bath is seasonal in practice. Kotohiki Kairo notes that it warms considerably between June and October, so it may not feel like a conventional cold plunge in summer. The Shodoshima soy-sauce barrel is a striking shape, but the water in it is cooled spring water, not soy sauce.
The operator’s monthly examples show how wide that swing can be: seawater is around 8–10°C in midwinter, but about 26–29°C in July through September. The spring-water plunges are listed around 15–21°C, while the single-person chilled bath can be set as low as 3°C; actual temperatures still vary with season and conditions. There is no need to treat the coldest setting as a challenge or stay in longer than is comfortable.
Admission and timing
Sauna use in the assigned bath area is included; towels and indoor clothing cost extra. Meal service has separate lunch and dinner hours, so check the restaurant schedule if you plan to eat after bathing.
| Regular visit | Current information |
|---|---|
| Adult admission | ¥950 weekdays; ¥1,100 weekends and public holidays |
| Bath and sauna hours | 11 a.m.–11 p.m. |
| Last reception | 10 p.m. |
The bath is also a natural hot spring, listed as a calcium-sodium chloride spring. The operator states that the water is filtered and circulated, heated by heat exchange, and may be diluted on busy days; chlorine-based disinfection is used. This is useful context if you are comparing “natural spring” with a strictly source-fed bath.
On an ordinary operating day, the facility’s rules exclude guests with tattoos. The September 12, 2026 Setouchi International Sauna Festival used a separate swimsuit-based format and allowed tattoos only when fully covered; that was an event rule, not a change to everyday admission. The 2026 event has passed, so check for a new event notice rather than relying on its old exception.
The published festival rates were separate from regular admission and included bath entry.
| Festival session | Advance ticket | Same-day ticket |
|---|---|---|
| 10 a.m.–2 p.m. | ¥3,700 | ¥5,000 |
| 3–7 p.m. | ¥3,700 | ¥5,000 |
Getting there
From JR Kanonji Station, the facility lists a taxi ride of about five minutes. It is not a five-minute walk from the platform. If you are travelling from Takamatsu, the limited express to Kanonji takes about 50 minutes, followed by the local taxi leg. By car, the listed drives are around 12 to 14 minutes from the nearest expressway exits.
For a no-car visit, make the bath the final stop of a half-day and check the return transport before you enter. The combination of sunset timing and the 10 p.m. last reception can make the evening feel flexible, but the station transfer still needs arranging.
Kotohiki Kairo is a strong fit for sauna fans who enjoy choosing between different room styles and want a coastal setting. If all you want is a quiet, quick soak—or one admission that unlocks every sauna at once—it is the wrong expectation to bring. For help distinguishing a spring’s classification from how a facility treats its water, see our guide to onsen spring labels.
If you are choosing between baths across this end of Kagawa rather than coming specifically for the sauna, the western Kagawa day-onsen comparison puts Kotohiki alongside the shorter-window and lower-cost alternatives.
