TOKYO — About two weeks ago, a superior at the publishing house where I work suddenly died. He was a well-known workaholic. With responsibilities to oversee the editorial department, he was working on the weekend to accompany a prominent writer to Hong Kong to negotiate a publishing deal.

On Sunday morning, he was awoken with a sudden and intensely painful headache. The author who was staying in the same hotel room rushed to the front desk to ask for an ambulance. It was too late.

His death was confirmed by a Hong Kong hospital, and his remains were flown back to Tokyo's Narita Airport, and finally arrived at the front gate of our company headquarters. When his wife and son stepped out of the hearse, all our company's staff went downstairs and put our palms together in prayer, facing the remains of the family.

When I returned to my office, I looked at my late colleague's desk, just next to mine. Printed documents were piled up. Books he hadn't finished reading were off to one side. Everything looked exactly as it was when he went to Hong Kong, as if he would be right back.

That cause of death was a stroke. But we could also say he died of overwork. Every few years, one colleague or another would drop dead in the same way. They were all only between 40 and 50 years old.

Though my colleague's death received no media attention, our company's largest partner — Dentsu, Japan's biggest advertising company — faced criticism last year over a worker's "karoshi" or "death from overwork."

Takahashi Matsuri, a 24-year-old working for Dentsu committed suicide last Christmas day, by leaping from a balcony in the company's dormitory. Last month, the woman's mother held a press conference to reveal that the month prior to the suicide, her daughter had been working as many as 105 hours per week, under what she described as a military-like management.

On September the 30, Japan's Labor Standards Inspection Office officially recognized that Matsuri's suicide had been triggered by the long hours and bad management, and it constituted a work-related injury. On October the 14, the Tokyo Labor Bureau carried out an internal inspection of the Dentsu headquarters, as well as its major branch offices nationwide.

As one of the world's top advertising and public relations firms, Dentsu had won a major marketing partnership with Tokyo 2020, for the summer Olympics. But the company is notorious for its abnormal working philosophy. For its corporate regulations, a former president had formulated 10 in-house rules, nicknamed the "Ghost 10 Constitution." Among these rules: "Once a task is started, one does not give it up. One rather dies if the goal is not reached!"

In ancient times, Japan imitated China's state system. The Japanese emperor was modeled on a Chinese emperor. Gathered around him were the aristocrats submitted to his authority, and thus formed the power structure of the country. Aristocrats eventually started hiring soldiers to fight wars for them — over time, though, these soldiers asked: "Why are we shedding blood for the aristocrats instead of for ourselves?" The subsequent coup against their employer, the emperor, as well as the aristocracy, led to Japan's first warrior regime: the Kamakura shogunate in 1192.

If one visits the museums specialized in the Edo period (1603-1867) during which samurai society was at its heyday, one finds very different artifacts from those of China's Palace Museum or other national museums. For instance, the so-called "treasures' at the Tokugawa Art Museum in Nagoya are all military objects, such as armor, swords and banners. Compared with the sophisticated objects found in Chinese museums, this all seems very plain and modest.

When one thinks carefully, whether it's the "onigiri" rice ball that annually sells 1.5 billion units in 7-11 convenience stores worldwide, or the bottled tea drinks, they can all be traced back to the rations of ancient Japanese soldiers. Japan's warrior society advocated frugality, which was absolutely distinct from the world of the Chinese Empress Dowager Cixi whose daily banquet was composed of hundreds of different dishes.

In 1868, the Meiji Restoration transformed Japan from a warrior society directly into a modern military state. Subsequently, Japan's corporate world would replace the army, defeated in 1945, as the conduit by which the warrior mentality was passed down. Though Japanese national patriotism has been diminished in recent decades, it has been replaced by a spirit of loving and loyalty to one's "kaisha," the company you work for. That Matsuri became the victim of Dentsu's "Ghost 10 constitution" can be explained by the Samurai spirit so deeply rooted in today's Japanese enterprises.

Japan's Ministry of Health, Labor and Welfare reports that in the past year, 2,159 work-related suicides occurred. As OECD data shows, on average, Japanese employees worked 1,719 hours last year. In Germany, the average is 1371 hours, and the global norm is some 1,500 hours.

One silver lining to the Dentsu incident is that now Japan has started to question the culture of overworking. Kabu.com, a large online securities company, has launched a system to encourage employees to go home on time and take a bonafide lunch break.

Meanwhile, an IT company called SI in west Osaka, has focused on comparing working hours to actual work efficiency. The company reports that SI's labor costs went up 4% last year, but sales have risen 16%. SI was selected in March as a model enterprise and was recognized by Prime Minister Shinzo Abe personally.

All that said, Mr. Abe is often spoken of as the person who works the longest hours in Japan. It is also said that people around him are increasingly worried about his health.