Kazumi Toro, a staffer at the Days Japan magazine, sends a proof via a fax machine. The publication often sends and receives news releases and documents by fax. (Noriko Hayashi/For The Washington Post)

TOKYO — In Japan’s businesses and bureaucracies, in home offices and hulking companies, the fax machine is thriving.

Yes, the clunky device has fallen out of favor in so much of the world, a refuge for dust bunnies and stray cover sheets. But it is humming here.

Japanese still fax party invitations, bank documents and shopping orders. Business people call the fax a required communication tool, used for vital messages, often in place of e-mail. In the early hours of last year’s nuclear crisis at the Fukushima Daiichi plant, operators informed the government of an emergency seawater injection by dialing up Tokyo and sending a fax.

Japan’s continued fax devotion may be an endearing quirk, what with the country’s reputation as a high-tech playland, all bright lights and flawless trains and chirping micro-devices. But it may also represent a deeper sign of the nation’s inability to change and to accommodate global standards, even as it cedes economic ground to Asian rivals such as China and South Korea.

“It goes back to the famous theory that there are two Japans,” said Serkan Toto, a Tokyo-based consultant for Japanese Web, mobile and social gaming companies. “One is very efficient and highly productive. The other is where things are very slow and there’s barely any innovation. Information technology is in that second basket.”

With their traditional reverence for paper and handwriting, the Japanese still see use for the analog world. Computer use lags behind that in other developed countries. Business meetings revolve around printed documents, distributed in binders of breathtaking heft. And at government ministries, fax machines spin and whir, the centerpieces of a busy bureaucracy.

What other device spits out a confirmation notice declaring its success?

“It’s reliable,’’ said Toyoko Yoshino, owner of a real estate company that is an hour outside Tokyo. She uses the fax machine almost daily, she said, because she trusts it.

Most international trade groups long ago stopped keeping track of fax machine statistics as the technology, in most places, grew obsolete. Experts point out that fax statistics are hard to track even for those who want to, because increasingly, the fax technology is folded into phones, Xerox machines and computers. But several of the world’s most prominent fax machine makers — including Brother, Sharp and Ricoh — are based in Japan.

So Japan, in a testament to its fax fascination, still tries. As of March, according to Japan’s Cabinet Office, fax machines could be found in 59 percent of Japanese homes. (That penetration rate, after climbing for years, has peaked in the past five years.)

Coming up with a similar number for the United States would require a “polite fiction,” said Jonathan Coopersmith, a Texas A&M University associate professor and an expert on the history of the facsimile. But even in the early 1990s, only about 3 percent of U.S. homes had the machines, he said.

In terms of fax reliance, “I don’t think any other nation comes close to Japan,” Coopersmith said.

In most places, computers — and by extension, e-mail — quickly made the fax machine unnecessary. But in Japan, that transition has not happened.

One reason is that computers, at the outset, never worked well for the Japanese. The country’s language — a mix of three syllabaries, with thousands of complex “kanji” ideograms — bedeviled early-age word-processing software. Until the early 1990s, Japanese was nearly impossible to type. Even today, particularly for older Japanese people, it’s easier to write a letter by hand than with a standard keyboard. Japan also relies on seals, called “hanko,” that are required for most official documents.

While the typing difficulties also apply to China, the country never got stuck in the fax stage, tech experts say.

Another factor in Japan: The government’s long-standing monopoly on phone lines kept high-speed digital Internet rates relatively high — particularly compared with South Korea, where the government promoted cheap broadband use.

Largely because of these hurdles, the Japanese developed a preference for surfing the Web on their mobile phones .

“A lot of homes just are not connected to the Internet,” said Andrew Horvat, a communications expert and the director of the Stanford overseas study program in Kyoto. “They all have phones, however, so that also makes faxing easier and cheaper than online communication.”

Even Japan, of course, is weaning itself off fax machines. Mobile giant SoftBank went “paperless” last month, both for environmental reasons and to save printing costs. Other companies say they don’t dare banish faxes — too many clients insist on them — but they would like to soon.

For now, many firms that offer services to consumers say that fax remains their preferred mode of communication. Even NHK, the national broadcaster, relies on faxes, as in a fee-based service offered to viewers of a weekly program, “Tameshite Gatten,” or “Try and Understand,” whose stories on health-related topics often feature healthful recipes.

The fax offer began in January 2011, and in that first year, 491,000 Japanese used the service, NHK spokeswoman Reiko Saisho said. Unlike with e-mail, those recipes came out warm, on standard A4 paper, and were perfect for filing away.

Special correspondent Yuki Oda contributed to this report.