Marintopia Resort, operated by Nishigaki Co., Ltd. (headquartered in Kyotango City, Kyoto Prefecture; President: Shunpei Nishigaki), has added a private sauna for up to two guests to "Migiwa," a guest room at Amanohashidate Rikyu HOSHINO-OTO, its one-villa-per-night property in Kyoto's Amanohashidate.
All seven villas at HOSHINO-OTO come with a natural hot spring and private pool, but Migiwa is the only one with a sauna. The room now brings together a sauna, an outdoor "Kin Onsen" (Gold Hot Spring), an indoor "Gin Onsen" (Silver Hot Spring), and a pool in a single villa, letting guests move between hot and cold without sharing the space or walkways with other guests.
Official website: https://www.hoshino-oto.jp/
Background
According to the Japan Tourism Agency's Travel and Tourism Consumption Trend Survey, domestic travel spending by Japanese residents reached 26.7845 trillion yen in 2025, with overnight trips accounting for 80% of that total at 21.7211 trillion yen. Average spending per trip rose 3.8% year-on-year to 48,359 yen — a sign that travelers are spending more per stay rather than traveling more often.
As the quality of a stay comes under greater scrutiny, bathing and sauna facilities at many properties remain shared. Wait times for the sauna and proximity to other guests can affect how a stay feels.
Since opening in 2017, HOSHINO-OTO has equipped all seven of its villas with a natural hot spring and private pool, offering stays where guests don't share paths with other guests. Adding a sauna now means the full warm-cool-rewarm bathing sequence can be completed inside a single guest room.
Migiwa was chosen for the first sauna because its pool — a "black pool" that isn't heated — can already serve as a cold plunge year-round. The room's separate outdoor and indoor baths, drawing from two different hot springs, also give guests more than one place to go after the sauna.
The New Private Sauna
The cabin-style sauna seats up to two guests. It's built from heat-treated wood and double-layer tempered glass, which distributes heat evenly through the room, and uses an electric heater from Estonian brand HUUM. The sauna stones can hold up to 55 kg — the more stones loaded, the more heat is retained, so the temperature stays higher for longer after löyly. Guests can use the sauna whenever they like, from check-in through check-out.
After the Sauna: Three Places to Cool Down
1. Pool — Depth 60–110 cm, water temperature around 20°C
Migiwa's pool is 60–110 cm deep with water around 20°C year-round. Three of HOSHINO-OTO's villas — "Ten," "Sei," and "Oto" — offer a heated pool option from April 1 to November 30 for an additional fee, but Migiwa's "black pool" stays unheated, so it can double as a sauna cold plunge without any extra step. It sits just outside the sauna, letting guests cool off in the sea breeze off Miyazu Bay.
2. Kin Onsen (Gold Hot Spring) — Outdoor bath, sodium chloride strong brine spring
The outdoor bath draws from "Kin Onsen." The property's official website lists neuralgia, muscle pain, joint pain, frozen shoulder, bruises, sprains, poor circulation, and fatigue recovery among its indications.
3. Gin Onsen (Silver Hot Spring) — Indoor bath, weakly alkaline simple spring
The indoor bath is fed by "Gin Onsen," with listed indications including lower back pain, neuralgia, frozen shoulder, sprains, poor circulation, peripheral circulation issues, and reduced digestive function.
Because the outdoor and indoor baths draw from different springs, guests can vary their route from day to day — sauna, then pool, then Kin Onsen, or sauna, then pool, then Gin Onsen — depending on how they feel.
About Amanohashidate Rikyu HOSHINO-OTO
Guest Rooms
On arrival, guests are welcomed in the lobby with a drink service intended to ease the fatigue of travel. Migiwa is a 120 square meter Japanese-style room for one to three guests, fitted with a 25 cm thick Tempur mattress. All seven villas have ocean views and sit on a hilltop overlooking the Sea of Japan and Amanohashidate.
In-Room Bathing and Sauna Amenities
The outdoor bath draws from Kin Onsen and the indoor bath from Gin Onsen — two different hot springs in one room. Combined with the new sauna, Migiwa now offers three types of bathing — Kin Onsen, Gin Onsen, and sauna — within a single villa.
Sauna ponchos and sauna hats are available to borrow. The room is also stocked with herbal tea for löyly, plus detox water and "Oropo" for rehydrating after a sauna session.
Dining at Kaon
At the on-site dining room Kaon, a chef finishes each dish tableside using live seafood delivered directly from Miyazu port, Kyoto Tamba beef, and pesticide-free vegetables from the local Tango area. In winter, a live crab course featuring Taiza crab is also offered.
Anniversary Plan
An anniversary package including a wall flower arrangement, gold-leaf sparkling wine, and a custom-made cake is available. This package is offered only in the Premium Room "Oto," not in Migiwa.
Facility Details
Facility name: Amanohashidate Rikyu HOSHINO-OTO
Location: 2686 Hioki, Miyazu, Kyoto Prefecture
Area: Kyoto / Miyazu (Amanohashidate)
Opened: April 1, 2017
Buildings: 7 total, each rented exclusively to one group
Site area: 2,846 square meters
Sauna-equipped room: Migiwa
Sauna specifications: Cabin-type, capacity 2, heat-treated wood and double tempered glass, electric heater (sauna stones up to 55 kg), app-controlled temperature
Migiwa guest room: 120 square meters, Japanese-style
Migiwa bathing facilities: Outdoor bath (Kin Onsen, sodium chloride strong brine spring), indoor bath (Gin Onsen, weakly alkaline simple spring), unheated pool (depth 60–110 cm, around 20°C), private sauna
Migiwa capacity: 1–3 guests
Access: Approximately 90 minutes by car from Osaka; approximately 20 minutes from the Yosa-Amanohashidate IC on the Kyoto Longitudinal Expressway / San'in Kinki Expressway
Official website: https://www.hoshino-oto.jp/
Future Plans
Nishigaki Co., Ltd. operates several one-villa-per-night properties in the Miyazu/Amanohashidate area, each with its own private sauna. With Migiwa's addition, another sauna-equipped room joins the area's lineup.
By pairing hot springs with saunas, the company aims to encourage longer stays and greater tourism spending in the Tango area.
