Inside Japan’s most beautiful bathhouses

For many, sento are still a vital part of daily life in Japan, each governed by a strict set of customs. For centuries these gender-segregated bathhouses have acted as ritualistic community spaces, meeting points and places for contemplation and relaxation. But numbers have fallen drastically in recent decades: from almost 18,000 bathhouses in the 1960s there remain only around 2,000 across Japan today. In recent years, these bastions of traditional living have become the focus of a new energy as efforts to preserve, revitalise and celebrate their cultural value have put them back at the centre of communal life.

Unlike outdoor onsens, which are built on natural hot springs, sento are situated indoors, typically fed by tap water and featuring high ceilings to let the steam rise to the roof. They’re often found in residential areas and vary depending on location, history and ownership; Miya-zukuri, for example, are traditional wooden bathhouses, architecturally similar to temples and shrines. “They were constructed by skilled carpenters who took extra pains to do their best work, gaining the respect of the neighbourhood,” says activist Sam Holden, who co-founded Sento & Neighborhood in 2020, a not-for-profit that works to protect and promote these endangered institutions. Super sento are large, commercial spas with added services such as massage treatments and restaurants.

Sento can be traced back as far as the sixth century, when spiritual purification by way of water was part of Buddhist and Shinto practices. Communal baths were initially found in temples but gradually spread, becoming accessible to the general public. Edo (modern-day Tokyo) welcomed its first sento in 1591, providing an essential daily service for a growing population living in cramped quarters without private baths. During the Edo period (1603-1868), Sento culture flourished and became the heart of neighbourhoods, a space for socialising and gossip. “Most people lived within a few hundred metres of one, and they were places of intergenerational communication,” says Holden. “Children would be watched or scolded by other community members” and the sento contributed to the growth of “strong local networks”. As the economy boomed after the second world war, private bathrooms became increasingly common and the demand for bathhouses diminished. Faced with high maintenance and running costs, ageing proprietors are struggling to find willing successors to take them over, and the survival of sento has become a common cause. 

One man in particular has been a pivotal force in reviving and preserving the bathhouse; architect Kentaro Imai has refreshed 23 public baths in Japan, recharging tired interiors with new but respectful designs. Imai started using bathhouses in his early 30s, becoming a regular patron. “At the time I simply chose to live in a room without a bath to save on rent, but this led me to realise the value of public baths,” he says. With his interest piqued, he established Kentaro Imai Architectural Office in 1998. Imai designs each project around a specific tailored concept. Goshiki-yu sento in Tokyo is a healing space, with its lighting and colours based on the yin-yang and five-elements theory (fire, earth, wood, metal and water). Fukuno-yu, situated in a traditional temple area in the north of the city, invites good fortune; it is infused with auspicious elements and draws inspiration from fusumae – traditional sliding doors painted with beautiful designs. Yoshino-Yu, in the east of the city, boasts a small courtyard garden (tsubo-niwa) and veranda (engawa) – features of older wooden sento that were mostly replaced by the coin-operated laundries that provided the bathhouse owners with a secondary source of income.

Some content could not load. Check your internet connection or browser settings.

In addition to these restorations, however, a new breed of sento is emerging, reaching a broader customer base and often reimagined as trendy hangout hubs with added amenities aimed at a younger demographic. “From the outset, I was looking for a new community that wasn’t a club or a bar,” says Jo Nagasaka, founder of Schemata Architects, which has revamped two bathhouses in Tokyo. Both offer craft beer, saunas and even a DJ booth for music events. 

Schemata’s Kogane-yu and Komae-yu bathhouses – the latter was completed in 2023 – both sit on the ground floor of reinforced concrete, multistorey apartment buildings. Within the bathing areas themselves, a partition wall separates genders but leaves a gap at the top – true of all sento. “It’s not as structurally stable but it is convenient for families who can call out to each other to check if they are ready to get out. Or perhaps to feel each other’s presence on the other side of the wall,” says Nagasaka. For Kogane-yu, Schemata’s first project in 2020, the firm was asked by third-generation sento owner Takuya Shinbo to redesign the space for young Tokyoites. The result feels industrial-chic: lockers are made from birch plywood, porcelain beige tiles (representing the human body) cover the floors, and walls are tiled or concrete. Nagasaka commissioned artist Iichiro Tanaka to create noren – split curtains – for the entrances of the changing rooms and baths, and manga artist Yoriko Hoshi to paint a mural of Mount Fuji.

Expansive, decorative artworks are one of the defining features of sento, giving the eyes a place to wander. It’s a highly specialised craft and there are only three sento muralists working in Japan at this moment. “It requires a deep understanding of the space and a particular speed of execution so that a bathhouse is only closed for one day,” says Stephanie Crohin, Japan’s sento ambassador and the author of three books on the subject. “Most of the muralists today have trained under the last generation of masters.” The scenes and landscapes depicted can depend on the region; in Kantō, which encompasses greater Tokyo, towering paintings of Mount Fuji are common. “It symbolises good fortune and tranquillity,” says Crohin, who has visited more than 1,000 sento and has seen portrayals of local landmarks, tiled copies of Magritte and Renoir, and paintings of Swiss castles.

Mieko Watanabe, the founder of architectural and interior design firm wAtelier, describes her Kuwamizu project as both a bathhouse and art gallery. The sento is situated in the city of Kumamoto on the island of Kyushu, and local designer Toshinori Yonemura was tasked with creating vignettes of a nearby lake, painted on Japanese cypress-wood louvres. “Walking in, the picture is hidden from view, but it unfolds and evolves as the bather sits, stretches and soaks, defying the perfect vantage point,” says Watanabe. This 2020 public bathhouse, with a soaring ceiling and grey terrazzo floors, was constructed in a private house. The area had suffered from a major earthquake, leaving many without homes. “Access to baths after such disasters makes you remember that you are Japanese. The steam and soap suds wash away the sweat and sorrows of the day,” says Watanabe. 

Sento are synonymous with community. The Japanese use the expression hadaka no tsukiai (“naked communion”) to describe the intimacy of a shared bath that enables open and honest conversation. Stripped of clothes and hierarchies, bathers of all ages, incomes and backgrounds soak side by side. It’s all part of the egalitarian spirit. “Sento bring together people from different walks of life,” says Watanabe. “And in times riddled with problems like deflation, ageing and population decline, the baths offer a unique place of respite.” 

Shinya Hayasaka is a medical doctor and professor at Tokyo City University, and has been researching the benefits of bathing for more than two decades. “Those who bathe up to seven times a week have a 24 per cent reduced risk of developing depression,” he says. Sento tend to have a number of baths at different temperatures (hotter tubs are favoured by older patrons), but Hayasaka advises that 40 degrees for 10 minutes is optimal. Some places infuse the water with minerals.

While the wellness boom has helped popularise Korean bathhouses – or jjimjilbangs – in cities such as LA and New York, the sento remain unique to Japan. This may not be the case forever. Watanabe and Nagasaka have visions of introducing a version of sento abroad, tapping into a growing appetite for healthy and spiritual living. “Sento are spaces that remain rooted in the ordinary rhythms of neighbourhood life,” says Holden. “They give people and families a sense of belonging and attachment to their local communities, so it’s important they continue to thrive.”