For her graduation thesis, Mizuki Tanaka, then an art history student at Meiji Gakuin University, chose to explore how the motif of Mount Fuji evolved into the most commonly used in murals decorating sentō (public bathhouses) dotting the capital. As part of her research, she attended a live-painting performance by Morio Nakajima, a master sentō mural artist who has been covering steamy bathhouse walls with depictions of Japan’s highest peak for half a century. Intrigued, she soon became his apprentice.

“The event triggered my curiosity and I asked whether I could see him at work. I began to learn that the occupation was desperately lacking fresh blood and could die out unless a younger generation inherited the art,” says Tanaka, 36, who is now one of Japan’s three remaining sentō mural artists alongside Nakajima and Kiyoto Maruyama, who are in their 70s and 80s, respectively.

From a peak of 2,687 in 1968, the number of sentō in the capital has fallen to approximately 560 as of December 2017, according to the Tokyo Sento Association. While the decline is attributed to the increase in the number of homes with baths during Japan’s rapid economic growth in the 1970s and ’80s, the retro charm and health benefits of visiting a sentō have been reevaluated in recent years. It is now considered a leisurely activity, an inexpensive luxury, with bathhouses serving patrons like community centers.

“Unlike one-off paintings, we return to our clients every few years to repaint murals weathered from the steam and humidity. That gives us a chance to observe our growth in craftsmanship while letting us learn about each locale,” Tanaka says. “In a sense, our work is never ending, and I find that fascinating.”

One theory dates the first sentō painting of Mount Fuji back to 1912, when an artist from Shizuoka Prefecture — where the 3,776-meter mountain looms — painted the sacred volcano on the walls of Kikai-yu, a bathhouse in Tokyo’s Kanda district.

Mizuki Tanaka at work on a mural. | COURTESY OF MIZUKI TANAKA

The concept of sentō murals quickly took off in the capital, with other bathhouses hiring artists to paint various landscapes to entertain bathers. Mount Fuji, however, remained the most commonly featured design due to its history as an auspicious symbol and its universal appeal.

The practice also transformed the walls of these bathhouses into an effective advertising medium, with local businesses running ads below murals. The sponsor fees from these clients covered the costs of hiring sentō mural artists, creating an efficient symbiosis.

Today, however, that custom no longer exists, leaving it up to the owners of sentō whether they want to or can afford to invest in decorating their tiled walls.

Tanaka says she paints, on average, around three to four sentō walls per month, spending the rest of her time attending related workshops and other events. With the 2020 Olympics on the horizon, she also receives requests from hotels and ryokan (Japanese-style inns) wanting to add some traditional ambience to their baths in other parts of Japan.

After being commissioned, Tanaka meets the sentō owners to brainstorm ideas. Some, she says, want neighborhood landmarks or regional festival mikoshi (portable shrines) depicted within the murals to add local flavor. Others may ask for the typical Mount Fuji, but painted in less familiar colors.

When it comes to the actual painting, Tanaka arrives at the sentō at around 8 a.m. to build scaffolding, often with the help of her husband. She brings containers of oil paint — the basic colors of red, blue, yellow and white — which she mixes into different colors, on the spot, on a wooden palette.

“Separately, I also prepare the color of the sky beforehand since I use that in large quantities,” she says.

Bath with a view: A Mount Fuji mural by Mizuki Tanaka, on the women’s side of Kogane-yu sentō. | COURTESY OF MIZUKI TANAKA

To cover wide areas, she uses paint rollers, while switching to brushes for more intricate details. Since the previous mural remains, she also calculates where each piece of a new design will fit while simultaneously painting over the old images. Including breaks, a day’s work to complete the mural usually doesn’t end before 8 or 9 p.m. She can’t finish on another day, since most bathhouses can’t afford to be closed for consecutive days.

“Nine times out of 10 I’m asked to paint Mount Fuji,” Tanaka says. “I aim for something fresh every time, however, changing the composition.”

Though, there are currently only three sentō mural artists, presenting the sentō experience itself as a unique Japanese cultural tradition appears to be gaining traction ahead of the Olympics.

The Tokyo Metropolitan Government along with the Tokyo Metropolitan Foundation for History and Culture and Arts Council Tokyo recently announced that it will be hosting what it calls the Tokyo Sento Festival 2020 next year between May 26 and Sept. 6. As part of the initiative, artists from different fields will paint the walls of four sentō in Tokyo, with Tanaka overseeing the efforts.

“Sento murals could once be seen across Japan, but toward the latter half of the Showa Era (1926-1989) they became mostly a Tokyo custom,” Tanaka says, seeing the initiative as a positive move. “If the number of sentō mural artists grow, we could eventually see walls of public baths in other parts of Japan decorated with paintings again.”