Sapporo Ainosato Onsen Nagomi

Visited Ainosato Onsen "Nagomi" on Sunday, October 26, 2025 at 9:00 PM. This is an interesting hot spring whose water quality has recently undergone a dramatic change. Originally excavated in 2005, it was a hypertonic, strong saline spring (orange, yellowish-brown) with over 33g of dissolved substances. After being used as a footbath for a while, the current hot spring facility opened in 2010. However, nearly 20 years later, last year, the dissolved substances suddenly diluted to 1.1g, 1/30 of the original amount, and it changed into a hypotonic sodium bicarbonate spring (a dark, moor-like spring). It's not uncommon for the quality of hot springs to gradually change due to various factors, but such a sudden and dramatic change is rare. Considering what happened based on hot spring analysis reports from before and after the change, it appears that initially, hot water from deep fossil seawater was probably being supplied. However, as a result of years of pumping, groundwater pressure weakened, and large amounts of low-temperature water from the shallow peat layer containing humus sank and flowed in. For reference, the hot spring analysis report for the "Ainoyu" hot spring and its characteristics over time are described below. Before the change: [2005 (Heisei 17)] Flow rate: 230 liters, spring temperature: 43.4°C, pH: 6.8, Dissolved substances: 33.28g, total components: 33.33g, Metasilicic acid: 135.9mg, metaboric acid: 65.5mg, Free carbon dioxide: 53.0mg, The spring quality is a hypertonic, neutral, high-temperature sodium-chloride strong saline spring (strong saline spring). The water is slightly yellowish, transparent, strongly salty, and odorless. Its density is nearly four times that of human body fluids, exceeding that of seawater. Its distinctive fossil seawater originates from this water. It is yellowish-brown and cloudy, thick and sticky, and when it dries, it becomes "hot water," with a slightly tingling, tight feeling. After: [2025 (Reiwa 7)] Volume unknown, spring temperature 26.9°C, pH 8.1, Total dissolved substances/components 1.168g, Metasilicic acid 95.4mg, Metaboric acid 8.1mg, Humus 0.2mg, The spring quality is a hypotonic, weakly alkaline, low-temperature sodium bicarbonate chloride spring (containing sodium bicarbonate). While it appears slightly brownish, transparent, and odorless, it's actually a deep-black moor spring, similar to kuroyu (black hot spring water). It's thick and non-sticky, leaving the skin feeling smooth and moisturized, making it a "beautiful skin bath." The listed humus (humic acid, fulvic acid) content is a mere 0.2 mg, but it likely contains a high amount of humic acid, a high-molecular-weight organic compound that doesn't dissolve even in alkaline solutions and is filtered out. This likely forms complexes with metal molecules, increasing the black color. Unfortunately, I haven't experienced the previous spring quality, but knowing both, I think this hot spring truly demonstrates the power of hot springs as living organisms, constantly evolving like living things. Open 10:00-23:00, Adults ¥500 (cash payment). Shoeboxes and changing lockers are free. There are no free amenities like soap, but there are two Kozumi hair dryers (KHD-2690) for 10 yen per 3 minutes, a Tanita scale, and an Iris Ohyama electric fan. The indoor bath area features 5x3 + 6x3 separate faucets for showers and hot water, two shower booths, a medium-temperature bath (40°C), a low-temperature bath (38°C), an electric bath, a vibrating bath for three people, a cold bath (23°C), a dry sauna (3 levels for 10 + 5 people, with a TV and a 5-minute hourglass), and an open-air bath and an outdoor bathing area with four chairs and one reclining chair. There were three empty tub baths in the corner of the open-air bath, so it's possible that there used to be tub baths there. There's a small rest area and snack bar inside the building, where you can relax over a quick, inexpensive meal. There's also a Secoma and barber shop on the premises. This time, I enjoyed some delicious fried rice while contemplating the wonders of nature and hot springs.

This highly rated day-trip hot spring facility is located in Sapporo's Kita Ward. The mild, thick, moor spring water leaves your skin feeling silky smooth after a bath. 😉 The indoor baths include a jacuzzi and electric bath, and there's even an open-air bath. 😊 After 15 days of driving through snowy Hokkaido, my sciatic nerve was at its worst. The electric bath here has such a powerful output that it initially contracted the base of my femur. It hurt so much I jumped out of my seat, but I ate curry and ice cream in the cafeteria and took three baths, each time relaxing in the electric bath. After spending half a day like this, my sciatica surprisingly eased, and I felt a significant relief from my lower back to my thighs. The water was a deep brown color with no strange smell, and it was incredibly pleasant. ♨️

2026/03/06 You can get in for 380 yen on Jalan right now! It's on the edge of Ainosato. No amenities, hair dryer costs 10 yen for 3 minutes. Coin lockers and baskets available. Hot spring. Crowded. ① Free-flowing hot spring water. ② Weak against the strongest shower. ③ Compact. There are 6 types of baths, including cold baths and open-air baths. The bathtub can only fit 3 to 4 people. ④ The hot spring is hot. ⑤ Hair dryers are available for an additional fee, with space for 2 people, so you have to line up. Only chairs available to rest. Seems like snacks are available. The density is quite high.

Visited on October 15, 2025, during the daytime. When I handed my ticket and point card to the woman at the counter, she stamped my point card and then handed it to me with one hand, holding it between her index and middle fingers. I was impressed by this service, which I've never experienced anywhere else! (Anyone who has received proper education wouldn't do this even to family or friends.) Of course, there was no greeting when I left. Amazing! 👍 The changing room had a slight smell of cigarette smoke, and the tissue box was empty with no replenishment.

The best thing about this place is that it's only 500 yen for adults (until February 28, 2026). The hot spring water is a moor hot spring, and there's an open-air bath, jet bath, sauna, and even an electric bath, so the facilities are quite impressive for the price. It feels a little cramped, but light meals are available, and even in these times, you can get ramen, fried rice, and curry for just 550 yen. Soba noodles start at 350 yen. But be prepared for the taste! 😊