A 40-room hot spring inn perched on high ground in Atami, Shizuoka, began adding six rooms in stages from August 7. Two get barrel saunas, two get wall projection. The building already has a large communal bath and a sauna.
1.Atami Fuga has gone from 40 rooms to 46. The address is 16-8 Umezono-cho, Atami, Shizuoka, up a hill that costs about 1,500 yen by taxi from Atami Station. Two theater-room triples and two Japanese-Western twins opened on August 7, with two private-sauna twins following on August 14. The opening rate starts at 20,625 yen per person for two sharing a room, which the operator describes as a flat 25 percent discount.
2.The operator is Relo Vacations, founded in October 2004, capitalized at 50 million yen, headquartered in Shinjuku, Tokyo, led by Tamura Yoshikatsu. It runs more than forty lodging properties nationwide under the name Relo Hotels & Resorts. Parent company Relo Group is listed on the Tokyo Stock Exchange Prime Market, and for the fiscal year ended March 2026 it posted revenue of 151.07 billion yen and operating profit of 30.815 billion yen.
3.The 46 rooms fall into eight categories. The smallest, a Japanese-style twin in the main wing, is 22 sqm; the largest, the theater-room triple, is 46 sqm. There are seven twins with private open-air baths at 30 sqm, six Japanese-Western twins at 40 sqm, fourteen Japanese-style twins at 25 sqm, and three two-room Japanese suites at 36 sqm. All six of the new rooms clear 35 sqm.
4.The private-sauna twin is 36.5 sqm and sleeps three, with a barrel sauna and a jacuzzi bathroom inside the room. The theater-room triple puts three semi-double beds in 46 sqm and throws video onto the wall. The Japanese-Western twin attaches a Ryukyu tatami room within 40 sqm. None of the three is sized for a solo guest.
5.Atami water is chloride and sulfate, so it wraps around the skin. The communal bath runs from 3 p.m. to 1 a.m., then again from 5:30 to 9 a.m. At eleven at night the loudest sound in there is the glass door sliding, not the water, and the heat spilling out of the sauna door carries the smell of wood. Bring a sauna into the room and that sound and smell move from the corridor into the guest room, which is why exhaust and water supply have to stand alone per room.
6.The sauna in this building is men only. What women get instead is the stone bath. Sitting in heat and then stepping into cold water was a sequence women, families and couples could not run inside this building, and putting a sauna in the room aims straight at that gap.
7.The 25 percent opening rate of 20,625 yen per person puts the list rate at 27,500 yen per person, or 55,000 yen for a room of two. The property's existing budget plans run 10,000 to 13,000 yen per person with dinner and breakfast. Same hot spring, same dinner buffet, and swapping only the room more than doubles the per-person rate.
8.HotelBank, which compiles hotel data, counts 76 ryokan and 2,508 rooms in Atami with an average rate of 59,300 yen, climbing to 67,900 yen in the peak month of August 2025. At 55,000 yen the sauna room sits below the Atami average. This is less a case of building an expensive room than of a cheap inn finally owning a room near the market average.
9.Someone has already measured what an in-room sauna adds to the price. HotelBank ran public rates collected by Metro Engine across 7,121 properties from January 2017 to June 2026 and found sauna-equipped rooms selling 47 percent higher on average, 32 percent at the median, within the same hotel. Work the median backwards from 55,000 yen and the room without a sauna prices at 41,700 yen, leaving a premium of roughly 13,300 yen.
10.At 70 percent occupancy the room sells 255 nights a year, and the premium alone brings in 3.39 million yen. In Japan a barrel sauna typically costs 1.5 to 3 million yen for the unit, plus another 1 to 1.5 million yen for indoor installation and fire compliance. Call it 2.5 to 4.5 million yen per room. At that price payback lands between nine and sixteen months, and even at 50 percent occupancy it does not pass two years.
11.Widen the frame to the whole property: 46 rooms at a rate of 35,000 yen and 75 percent occupancy give annual revenue of 440 million yen, roughly 4.1 billion won. The six new rooms price higher, and at 50,000 yen they produce 82 million yen, about 770 million won. Six rooms, 13 percent of the count, take 19 percent of revenue. Rates are not fully published, so these figures are this article's estimate.
12.The paths that fill these rooms are not the usual ones. First comes membership: buy points and use properties nationwide for life, at 2,199,200 yen in year one and an annual fee of 99,000 yen thereafter. When a member actually stays, the room charge starts at 8,000 yen for four or five people. Second comes the group's core business, outsourced employee benefits, where Relo Club holds contracts with 25,800 companies and organizations covering 13.4 million members who come in at preferential rates. Third comes the ordinary booking sites.
13.Where a full-service hotel would earn from banquet halls and weddings, this company fills the gap with membership prepayments and corporate contracts. That is why a 46-room property does not have to chase booking-site rankings, and in exchange the business only turns if members come back. A company that sold a lifetime membership faces the same guest for ten or twenty years, so identical rooms year after year quietly cut the value of that membership.
14.So these six rooms are not construction that adds supply. They sell a new reason to guests already secured. A room with a sauna, a room where you can watch a film, a room with tatami. All three exist to make a returning guest say "that one this time," and because the in-house sauna is men only, the experience half the guests could not use is resold by the room.
15.The market helped. Atami counted 3,199,457 overnight guests in fiscal 2025 on a bathing-tax basis, up 4.2 percent year on year and the highest since fiscal 2001, while national overnight stays fell 1.8 percent in the same year. The tourism bureau counts more than 350 rooms added in the city in fiscal 2025 alone. Plenty of operators are adding rooms against the incoming demand, which leaves whoever adds late with no option but a room nobody else has.
16.The operator noted in its release that the new room images include AI generation and retouching. It is selling a room that has not opened through a picture that was generated, with a 25 percent discount attached to take bookings in advance. A membership business is precisely where complaints cost the most when the real thing fails to match the picture.
In closing
A 40-room hot spring inn added six rooms, filled every one of them above 35 sqm, and put into two of them the same sauna the building already had downstairs. The rate is 27,500 yen per person, more than double the existing budget plans, and stripping out the sauna premium alone returns the 2.5 to 4.5 million yen of equipment within about a year. Doing this in Korea means standing first at the public health office. The Public Health Control Act sets facility standards for bathhouse businesses that separate bathing room, changing room and sweating room and require division by gender, and whether putting a sweating unit inside a guest room counts as lodging equipment or as a separately registered business is decided differently by each local authority. Add the electrical capacity upgrade for a sauna heater and the fire separation and exhaust plan, and meeting the local health office and fire department beats opening the drawings first.