Thirty years ago when Keio University sociologist Junko Kitanaka first started to study Japan’s culture of working oneself to death, it was considered a novelty overseas.
In the 1990s, stories of mostly middle-aged businessmen working so many hours that they would drop dead from a bodily failure, or opt to end their lives rather than return to the office, were received outside Japan as a peculiar cultural phenomenon. 
When Kitanaka presented to academic audiences in Europe and North America, she says they did not understand the mentality of people who wouldn’t go see a psychiatrist and who were driven to die for work.

A few decades later, the idea isn’t so alien. The pandemic has triggered widespread concerns about the physical and psychological toll of prolonged stress, sleep deprivation and social isolation. A landmark study by the World Health Organisation (WHO) and the International Labour Organisation published earlier this month found that 745,000 people died in 2016 from stroke and ischemic heart disease as a direct result of having worked at least 55 hours a week.
For the first time on a global scale, long hours at work have been established as responsible for about one-third of all deaths. Frank Pega, WHO’s technical lead on the study, says that despite clear evidence linking overwork to death, for 20 years “we had overlooked this risk factor”.

Not so in Japan, which coined a name for this problem: karoshi, which literally means death by overwork. After the 1973 oil crisis triggered widespread workplace restructures, reports emerged of worker fatalities, most often from heart failure, stroke or suicide. Most victims worked long hours – sometimes 60 or 70 hours per week or more – in the lead-up to their deaths.
Since then, pressure on workers has continued to mount. Irregular worker numbers in Japan are up from 10 per cent in 1990, to 40 per cent, while those on full-time, regular contracts do not feel able to quit, no matter how intolerable work becomes.

The government accepts around 200 workplace injury claims for karoshi annually, but campaigners have put the toll at around 10,000 deaths. A hotline run by the National Defense Council for Victims of Karoshi to seek government compensation for work-induced stress, disease or disability receives between 100 and 300 calls every year.
Makoto Iwahashi, of the labour rights organisation POSSE, says victims’ families have been instrumental in raising awareness of karoshi: “People know that there is a risk that you’re going to die if you work long hours, which wasn’t common sense 30, 20 years ago.”
In 2018, president Shinzo Abe presented the “Work Style Reform” bill, which meant employers could be forced into compelling employees to take holidays, a response to the 50 per cent take-up of paid leave. But other gaps in the law enabling chronic overwork were allowed to continue. For the first time, a cap was introduced on overtime – but it was set perilously high, at 80 hours a month. On top of an eight-hour day, that averages to a 60-hour week of overtime.
The Japanese government recognises more than 80 hours’ of overtime a month as a risk factor for karoshi, yet it not only made it legal to work up to that line; it introduced an exemption for “special months” of 100 hours’ overtime, to be sought at employers’ discretion. “The government is saying, ‘if you work to this threshold, then you could die – but you can work to this threshold’,” Iwahashi says.
For anti-karoshi campaigners, the reforms handed employers greater flexibility to extend workers’ hours and obfuscated the “karoshi line”. These uneasy alliances between governments, companies and workers are hardly unique to Japan. The UK allows zero-hour contracts; in the US, overtime is unfairly distributed. The social movement against karoshi has inspired similar initiatives in Korea and China.