Established in 1903, this establishment is currently in its 5th generation and operates as a day-use bathing facility with overnight stay options. It seems that there used to be a red-light district in the past, reflecting the deep history of the place. The bathing fee is 600 yen (950 yen if using the rest area set). The facility, although old, is well-maintained with small changing rooms and bathing areas. There are two baths with different spring qualities, both sourced from natural springs. 1. Large bath: "Bicarbonate spring" (sulfur-sodium-chloride-carbonate hydrogen cold mineral spring) 2. Small bath: "Salt spring" (sodium-chloride spring). The water in this area is a dark brown color, the darkest in the surrounding areas. While there are claims online about the high content of humic substances (moor) in the water, there is no solid evidence to support this. However, the water is definitely good for the body. In my experience, this water type promotes sweating and is likely beneficial for the skin. The large bath can accommodate 3-4 adults, while the small bath is suitable for 1-2 people. There are 5 sets of showers available. After bathing, you can purchase mineral water from the vending machine, which has a clear and refreshing taste. Due to the small bathing area, I recommend visiting on weekdays, especially for beginners or those who are shy.

I was planning to visit this hot spring in July 2022. It is marked by a torii gate. Matsubara Onsen Ryokan opened in Meiji 36. It features a coffee-colored slippery water with a high content of humic substances (moor). The baths offer two different types of water: sodium bicarbonate spring and weak salt spring, both with hot and warm options. The water is source-heated and flowing, leaving the skin smooth. There is also a drinking water tap, with the sodium bicarbonate spring said to have benefits for diabetes, digestive inflammation, and liver health, and is popular for being "delicious." However, the baths are small and can get crowded with just three people. In addition to day trips, there are packages that include use of the rest area and bathing fees, allowing guests to stay all day and bathe multiple times like a therapeutic stay. It was the darkest hot spring I have ever visited. Since it only has indoor baths, I couldn't stay for long, but it was very satisfying. The showers are not sourced but do not make the hair stiff, perhaps due to the lack of chlorine. The women's changing room has lockers for clothes (without keys), but no washbasins or hair dryers, which are available in the hallway for a fee (one shared between men and women). Personal hair dryers are not allowed. When I visited, it was a private experience, but I imagine it could be awkward with other people around. There are valuable item lockers next to the reception, vending machines, and a rest area available. I would like to visit on a weekday next time.