Yamaguchi Onsen in Kai: A Low-Temperature, Source-Flowing Bath
Yamaguchi Onsen in Kai uses unheated spring water, so expect a cool soak; confirm current indoor temperature and outdoor-bath availability.
Checked: September 27, 2026
Yamaguchi Onsen is a small day-use bath in a residential part of Kai, near Route 20. Kai City describes its spring as unheated and source-flowing, at around 37°C. That is mild even under normal conditions.
Recent visitor reports from 2026 say the bathing water felt much colder and the outdoor bath was out of service. These are visitor observations, not an operator announcement. Ask what is open and how warm the indoor bath is before setting out.
The facility is a better match for people who specifically want a long soak in low-temperature water. If you expect a hot pool, sauna, restaurant or resort-style rest area, this is not the right stop. The municipal listing describes a small rest room, but does not advertise a broader set of amenities.
Hours, prices and the information gap
Kai City’s current visitor portal lists the following details; the older 2019 Pure Onsen Association profile differs and says children were not admitted at the time because of pandemic restrictions.
| Detail | Current visitor portal | 2019 profile |
|---|---|---|
| Hours | 9 a.m.–9 p.m.; last admission 7:30 p.m. | Older hours |
| Closure | Monday; Tuesday if Monday is a public holiday | Different listing |
| Adult admission | ¥600 | Older rate |
| Child admission | ¥400, age three through elementary school | Children excluded under pandemic-era restriction |
Since the listings do not agree on every detail, call 055-279-2611 to confirm the current price and child policy. Carry cash as a practical precaution.
The association’s profile records a 36.2°C source and describes the baths as unheated and supplied directly from the spring. That is an older analysis and certification record, not a current measurement of today’s bath. More recent visitors have described water in the low 30s Celsius; the operator does not publish a current daily temperature or a clear notice about the outdoor bath’s status.
Getting there
The address is 477 Shinohara, Kai City, and the city portal lists parking for 25 cars. This is not a station-front bath. Ryuo Station is roughly 2 km away, and the Enoki Post Office bus stop is a short walk from the entrance, but confirm the bus timetable and return connection before relying on public transport. A taxi from Ryuo is the simpler rail option if the schedule does not line up.
Should it go on your itinerary?
Visit when a cool, unheated soak is exactly what you want and you have room to change plans if the outdoor bath is still closed. The setting is local and unpolished, and that is part of its character; the trade-off is that current facility conditions are not as clearly published as the standard hours. For a more predictable day-bath stop nearby, compare Yumemi no Oka or Ryuo Radon Yutopia.
