“Scenic open-air baths” are a powerful motivator when choosing a ryokan. Yet such evaluations are hard to discern from room types or price lists. In this report, we apply natural language processing to guest reviews actually posted by overnight guests, aggregating mentions related to experiential quality—such as “open-air bath,” “view,” “free-flowing hot spring,” and “water quality”—by region. Rather than using price or ADR, we use the qualitative axis of guest reviews to surface both the highly rated regions for scenic open-air baths and, conversely, regions where such experiences are scarce.

Measuring “Scenic Open-Air Density” Through Reviews

The starting point of this analysis is positive mentions in reviews that combine “open-air bath” and “view.” Standard star scores average together many elements—cleanliness, service, food, and so on—so it is hard to see “whether the scenic open-air bath is the star of the property.” We therefore aggregated, for each region, the share of total reviews that spoke positively about the open-air bath (the open-air mention rate). The higher this value, the more it means “ryokan in that region position open-air baths and scenery at the heart of the guest experience, and guests are actually leaving with that strong impression.”

Nationally, positive mentions of open-air baths were densest in Shizuoka, where the average open-air mention rate across target properties reached 25.3%. That works out to one in every four reviews discussing the open-air bath or view. We can confirm that the seaside hot-spring areas of Izu and Atami draw outstanding support for their ocean-view open-air bath experiences. Following these are Niigata (21.5%), Fukushima (20.5%), Gifu (19.8%), and Gunma (18.9%)—lining up the inland mountain hot-spring regions. The structural gap between an onsen area’s name recognition and guests’ actual satisfaction has been examined separately based on 955,000 reviews.

Source: HotelBank Editorial Team research (NLP analysis; average open-air mention rate across target properties in each region)

What stands out is that famous onsen destinations such as Oita and Wakayama (Shirahama) do not monopolize the top tier. Instead, regions that can pair scenery with open-air—Shizuoka with the Izu Peninsula, Niigata and Fukushima as meccas of snow-view open-air, and Gifu with Okuhida and Gero—exhibited the highest mention rates. The differentiator for these areas is not the sheer number of open-air baths but rather the strength of impression left by open-air experiences fused with scenery.

“Breadth” and “Intensity” of Top-Rated Regions

The strength of scenic open-air baths has two axes. One is breadth—how widely distributed the densely mentioned properties are. The other is intensity—the height of mention rate per property. Sorting regions along these two axes reveals each area’s individual character.

Shizuoka is top class on both axes: properties with open-air mention rates above 20% hit our aggregation cap of 100 facilities, and the average mention rate is the densest at 25.3%. It can fairly be called the overall leading region for scenic open-air baths, combining supply depth with experiential intensity. By contrast, Tochigi, Nagano, and Hokkaido are also broad regions where the count of target properties reaches 100, yet their average mention rates settle in the 12–16% range. This is because a wide mix of price ranges and property types coexist—business, sightseeing, ski—so multi-purpose stays are included, indicating that “properties where scenic open-air is the lead” and “properties where it plays a supporting role” coexist.

Conversely, Niigata (68 properties, 21.5%) and Fukushima (49 properties, 20.5%) do not match Shizuoka in facility count, but the per-property intensity is striking. These are regions where the clear theme of snow-view open-air baths is etched strongly into guests’ impressions.

Source: HotelBank Editorial Team research (NLP analysis). Horizontal axis = target property count (top-mention, capped at 100); vertical axis = average open-air mention rate

Regions Where Scenic Open-Air Is “Scarce”

On the other hand, the regions where scenic open-air bath experiences are relatively scarce are clear. Tokyo (open-air mention rate 6.6%), Osaka (7.6%), Okinawa (8.3%), and Kyoto (10.3%) all show low shares of open-air bath and view mentions in reviews despite large lodging demand. This is presumably because urban-area stays are centered on business or sightseeing access, and the supply of properties equipped with open-air baths is itself limited.

Read the other way around, this means that properties in these regions able to showcase scenic open-air baths can hold a strong differentiation point in reviews. In fact, on Tokyo’s bayside areas, high-floor ocean-view public baths gather voices such as “open until 6 a.m.” and “the view from the 15th floor is the best,” confirming that the combination of view and bath is valued even in urban settings. In Okinawa, while the open-air mention rate itself is low, support for baths overlooking the sea is tenacious, indicating ample room for growth if supply expands.

Source: HotelBank Editorial Team research (NLP analysis). Low open-air mention rate = regions where scenic open-air experiences are relatively scarce

Kyoto, with an open-air mention rate of 10.3%, leans toward the scarce-region side, yet its ADR for May 2026 was ¥47,300 (+24.7% YoY)—among the highest-priced regions nationwide. It is a market evaluated through different value axes such as machiya townhouses, gardens, and location rather than open-air baths, suggesting that a differentiation distinct from scenic open-air is functioning. The meaning of scarcity differs region by region, which deserves note.

Water Quality and Free-Flowing Source: A Second Qualitative Axis

Alongside scenic open-air, the qualitative axes of hot springs discussed in reviews are “water quality” (sen-shitsu) and “free-flowing source spring” (gensen kake-nagashi). Looking at properties with the densest positive mentions of water quality, names such as Gero Onsen Suimeikan (Gifu Prefecture, 293 of 1,796 target reviews = 16.3% mentioning water quality) and Ureshino Onsen Hotel Kasuien (Saga Prefecture, 190 of 802 = 23.7%) rise to the top. These are cases where water-quality traits such as “egg-skin smooth” and “bihada-no-yu” (beauty bath) have become the very brand of the ryokan.

For free-flowing source springs, smaller properties tend to have higher mention rates. Musouan Biwa in Toi Onsen of West Izu (Shizuoka Prefecture) sees 11.1% of its 307 reviews mention free-flowing source springs, confirming that the small-scale strategy of promoting bath freshness with a limited room count is clearly supported in reviews as well. The “visual” of scenic and the “tactile quality” of water and free-flowing source are different directions of hot-spring value a property can promote, and properties able to combine both retain room for growth.

Source: HotelBank Editorial Team research (NLP analysis). Top properties by positive mention rate for water quality (past 24 months)

ADR and Experiential Value in Top-Rated Regions

Top-rated regions for scenic open-air baths are not necessarily ultra-premium in price. Looking at average regional ADR (all-plan average) as of May 2026: top-ranking Shizuoka is about ¥36,000, Gunma about ¥33,700, Gifu about ¥30,000, and Nagano about ¥30,700. Meanwhile, Fukushima (about ¥25,700), Tochigi (about ¥27,700), and Niigata (about ¥27,100) have relatively restrained ADRs despite high open-air mention rates. In other words, there exist regions where the experiential value of scenic open-air remains at moderate price levels.

This can be read as regions that retain a sense of value for guests—”strongly supported for scenery and bath quality, yet still moderately priced.” At the same time, viewed from the operator side, in regions where there is clear evidence of experiential value (high open-air mentions in reviews), there is room to expand revenue opportunities through staged pricing and an expanded set of premium plans. How to connect the qualitative strength of scenic open-air to pricing strategy will become a key theme going forward.

Source: HotelBank Editorial Team research (NLP analysis) + MetroEngines Research (ADR, May 2026)

Summary

Viewing scenic open-air baths through the qualitative lens of reviews surfaces regional individuality that price lists alone cannot capture. Shizuoka is the overall leader combining supply breadth with experiential intensity, while Niigata, Fukushima, Gifu, and Gunma are top-rated regions whose per-property mentions are dense, anchored by snow-view and mountain open-air baths. Conversely, in Tokyo, Osaka, Kyoto, and Okinawa, scenic open-air bath experiences are relatively scarce, and this represents a differentiation opportunity for urban properties that can showcase view plus bath.

Layered on top with the “tactile quality” axes of water quality and free-flowing source springs, the directions of hot-spring value a property can promote become multi-layered. Scenic (visual), water quality (touch), free-flowing source (bath freshness)—visualizing these from review data brings each region’s and each property’s strengths and growth potential into more three-dimensional view. In top-rated regions where ADR remains moderate, room is left to connect experiential value to price.