The first question to ask about a company like Kongo Gumi is why it stuck around so long in the first place. For one thing, these companies tend to be clustered in industries that never really go out of style. Kongo Gumi specialized in building Buddhist temples—a pretty dependable bet in nation with a strong Buddhist history. The company's first temple, near Osaka, was completed in 593, and has been rebuilt six times since then (by Kongo Gumi, of course). “There’s a pattern,” William O’Hara, the author of Centuries of Success, told The Wall Street Journal in 1999. “The oldest family businesses often are involved in basic human activities: drink, shipping, construction, food, guns.”

The other reason these companies proliferate in Japan is because of how the country's family-run businesses have been passed down through generations. Japanese business owners typically bequeathed entire companies to their eldest sons, and there's a 10-foot-long 17th-century scroll tracing all of Kongo Gumi's previous owners. But what fostered corporate longevity was that owners were permitted some leeway if they didn’t trust their offspring to take the helm: They could adopt a son, who would often marry into the family and go on to run the business.

“The continuity component is surely helped by the custom of adopting (adult) sons to carry on the business, displacing ‘natural’ sons when direct progeny are not viewed as suitable,” Mike Smitka, a professor of economics at Washington and Lee University, wrote in an email. Japan’s oldest companies are thought of as family-run, but that’s something of a misnomer. “The continuity is in part fictive,” Smitka says.

In Japan, a 2011 study found, businesses run by adopted heirs consistently outperformed those run by blood heirs. This explains a bizarre statistic about Japanese family life: Unlike in the U.S., where most adoptees are children, 98 percent of Japan’s adoptees are 25-to-30-year-old men. “You can’t choose your sons, but you can choose your sons-in-law,” goes one Japanese saying.

So if they made it 500 or even 1,500 years, why would any of these companies collapse now? The most compelling explanation has to do with how the Japanese government has changed the way it treats struggling companies, according to Ulrike Schaede, a professor of Japanese business at U.C. San Diego. Historically, Schaede says, Japanese banks helped out even the most hopeless businesses without a second thought. “Between 1955 and 1990, only something like 72 Japanese companies went bankrupt. The reason was that the banks were supposed to bail them out,” Schaede says.

Then, in 2000, Japan passed its first Chapter-11-like bankruptcy law, and four years later, rewrote 1922 laws concerning corporate liquidation. This changed the default fate of troubled businesses. “Non-performing companies no longer receive help from lenders unless they have a solid plan for change,” Schaede says.