In 128 AD, the Roman Empire is starting to teeter, but architect Lucius Modestus has a secret plan. He resolves to save civilization by introducing it to numerous new inventions that he has stolen from a magical land, the domain of the “flat faces”. The magical land is modern Japan, to which he has somehow found a secret portal through a bath-house drain. Lucius is charmed by such newfangled notions as the bidet, the milkshake, and the giveaway toy—all of which he is sure can delight the citizens of Hadrian’s Rome.

If written ten years later, this might have become an isekai story with a lame title like I Drowned in Ancient Rome and Woke Up in Japan Where I Learned About Marketing. But the 2008 publication date for the first volume of the Thermae Romae manga kept it classily Latinate, infused with its creator Mari Yamazaki’s fascination with the classical world, and peppered with her hectoring rants about modern-day European hygiene. Its movie incarnation, in particular, emphasized the very personal nature of her storyline—despite being played for laughs, it is also the tale of a struggling manga artist who finds herself sharing her life with a man who knows a lot about the Roman Empire.

Yamazaki’s life is packed with enough incidents to be worthy of a manga itself. Dropping out of school in her late teens, she moved to France to study art. There, she was hectored by an old man from Italy, Marco, who was aghast that she was (a) traveling unchaperoned, and (b) missing out on all the art in Italy. Appointing himself her guardian, he steered her into studying in Florence and with him at the Vatican Art Museum.

On a brief return trip to her native Japan, Yamazaki was seriously injured in a car accident. She returned to Italy, shacked up with her Italian neighbor (a poet), got pregnant, and ended up as a single mother in Florence and Havana—a subject which became the basis for A Manga Artist at the End of the World, the autobiographical comic she wrote to pay the bills. She returned to Japan to teach Italian, and also, for some reason, became a roving hot-spring reviewer for Hokkaido local TV.

No, wait, there’s more. Eventually, she married Marco’s grandson, Beppi Cuppini at the Italian Embassy in Cairo. Beppi was a researcher in comparative literature, whose work dragged the couple all over the world, from Syria to Portugal to the USA. He was also an obsessive Roman history buff, whose reaction to Japanese baths gave her the germ of an idea for her big manga hit. Yamazaki was intrigued by the lack of public baths in Europe, even though their ruins were all over the place from the ancient world. It was this juxtaposition of ancient and modern that led her to create her account of a Roman man who finds a time-tunnel to modern Japan, and uses it to invigorate the ancient bathing experience.

Although Yamazaki received a paltry million yen for the movie rights, a live-action film went into production starring heartthrob Hiroshi Abe as the manga’s Lucius Modestus. It turned out that some of the majestic sets built for the sadly truncated HBO series Rome (2005) were still standing, allowing the Japanese cast the chance to cavort around scenery that looked far more salubrious than one might expect for a low-budget movie.

But before the film was even out, Thermae Romae got another incarnation, as an anime series designed to feather the media nest before the premiere. The anime version sneaked onto Fuji TV’s late-night Noitamina slot in January 2012, four months ahead of the movie. Noitamina’s reputation has been well-established for being a classy, often female-oriented programming block that eschews fan-bait and kiddie stuff, but the Thermae Romae anime was something of a change in direction—not because of its content, but because of its format. It was made by the animation studio DLE using Flash (now known as Adobe Animate), a versatile but decidedly cheapo software package best known in the anime world for its use by master-craftsman Masaaki Yuasa in films like Lu Over the Wall.

The film’s success led to a ridiculous number of media tie-ins and spin-offs, not the least a second movie, the advertising of which playfully reimagined Lucius in the pose of a time-traveling Terminator, wreathed, of course, in bath-house steam. Others included a world heritage exhibition at the Yokohama Museum of Art, and package tours offered to Naples and Pompeii. The Yunessun hot spring theme park (no, really, and it is not the only one in Japan), created a Roman themed bathing area, based on designs from Pompeii. It came with displays outlining the story of the manga, and even featured waterproof editions, so that people could read them in the bath. An anime sequel would eventually follow, along with Yamazaki’s own occasional chapters of a follow-up manga, revisiting Lucius twenty years on.

Elsewhere, the success of Thermae Romae became a springboard for fading local industries. There was once a time when many dwellings in Japan, particularly dorm-room accommodation, lacked anything approaching a real bathroom, requiring residents instead to walk over to a nearby public bath. I’ve been to one myself, in Arima near Kobe, and it was a delightful facility. Someone else had to scrub the floors and shine the taps, while my fellow travelers and I could shower beforehand, soak as long as we liked in bubbling volcanic water, and even nip into a certifiably authentic sauna (I am a Finnish citizen, it really was authentic). But such establishments have declined from being common on practically every city block, to relative rarities. With everyone and his dog suddenly interested in hot soaks, the Takatsu-yu public bath in Kawasaki rebranded itself as the “Thermae Furomae-yu” (a labored pun on the word for “bath”), and put up a mural based on the manga. It echoes a moment in the story where Lucius is inspired by a mural of Mount Fuji to start adding a little color to his bathhouse.

In 2017, Mari Yamazaki became the first manga artist to be made a Commander of the Order of the Star of Italy, a grand honor which she shares with notables including Luciano Pavarotti, John Turturro and Jamie Oliver.

The Thermae Romae anime is available from MediaOCD.

Jonathan Clements is the author of Anime: A History.