A Decade of Japan’s Karoshi Prevention Law: Lessons Learned (Oct. 2025)

Cheonghee Yu, Executive Committee Chair

Korea Institute of Labor Safety and Health

Translated by Michelle Jang

Reviewed by Joe DiGangi

Campaign to Enact Japan’s Karoshi Prevention Law

In Japan’s Act on Measures to Prevent Karoshi and Other Overwork-Related Deaths (hereinafter, the “Karoshi Prevention Law”), the term “karoshi and other overwork-related deaths” is defined in Article 2 as “death from cerebrovascular or cardiovascular diseases caused by excessive work-related burdens, or death by suicide caused by work-related severe psychological stress, including such cerebrovascular or cardiovascular diseases or mental disorders.” The law, enacted in 2014, was the result of persistent efforts by bereaved families of karoshi and overwork-related suicides, lawyers, medical professionals, experts, and concerned citizens, to address the overwork-related death issues that had been ongoing since the 1980s. During the late 1980s, at the peak of Japan’s asset price bubble, workers began collapsing and dying from overwork. Although the term “karoshi” had not yet been coined, reports of sudden worker deaths began appearing in the news. In 1988, a group of lawyers and medical professionals established the “Karoshi 110 Hotline” to provide consultation and support.

Bereaved families of karoshi and overwork-related suicides also began voicing their concerns to prevent such tragedies. They started organizing family gatherings, and in 1991, the National Association of Families Concerned About Karoshi was established. During the 2010s, these families appealed to society at large for the enactment of legislation to prevent karoshi, supported by lawyers, medical professionals, and other experts. Their efforts culminated in the Japanese House of Councillors passing the law with 239 votes in favor and none against, achieving unanimous cross-party support. This movement demonstrated that Japanese society recognized and took seriously the issues of karoshi and overwork-related suicides as pressing social issues requiring solutions.

So, what does the law entail? Article 1 establishes that the Act aims to promote measures to prevent karoshi and related deaths by conducting surveys and research on this socially serious problem. It seeks to contribute to realizing a society where such deaths do not occur, and where people can work in a healthy, balanced, and fulfilling manner. Crucially, the law provides a legal definition of karoshi and overwork-related suicides. Article 3 emphasizes conducting research to assess the state of overwork-related deaths in Japan, using the findings to develop preventive measures and raise public awareness of their importance.

Furthermore, Article 7 mandates the government to formulate an outline of measures for preventing karoshi and related deaths. These measures must be formulated by the Ministry of Health, Labour and Welfare in consultation with relevant administrative agencies and after collecting opinions from the “Council for Promoting Measures to Prevent Karoshi and Related Deaths.” which includes bereaved families and labor-management representatives. These measures are updated every three years, ensuring that bereaved families play a central role in prevention efforts.

The law identifies four key areas of prevention: research and surveys, developing and improving counseling systems, supporting activities conducted by private organizations, and other related measures. In accordance with Article 6, the government publishes an annual White Paper on the Prevention of Karoshi, reporting on the implementation of mandatory measures to prevent overwork-related deaths.

Ten Years After the Law’s Enactment: What Has Changed?

Regulating working hours is crucial for reducing karoshi and overwork-related suicides. However, even after Japan enacted the Karoshi Prevention Law in 2014, immediate implementation of working-hour regulations and reductions did not follow. It was not until 2018 that the Diet passed an amendment imposing penalties for violations of overtime limits.

The amendment set a monthly cap of 45 hours and an annual cap of 360 hours for overtime, with violations punishable by up to six months imprisonment or a fine of up to 300,000 yen. Nevertheless, the amendment faced criticism for containing numerous exceptions and failing to include overtime worked on holidays in its limits, leaving gaps in effective enforcement.[1]

Nevertheless, it is true that working hours in Japan have gradually decreased. According to annual statistics on working hours published by the OECD, Japanese workers logged 1,714 hours in 2009 (compared to 2,014 hours in South Korea). In 2015, the year the law came into effect, it was 1,719 hours (South Korea: 2,082 hours) and by 2023 it was 1,611 hours (South Korea: 1,872 hours), indicating a gradual reduction over time.

But what changes occurred in karoshi and overwork-related suicides before and after the law? In 2023, Makoto Iwahashi of the Japanese labor organization POSSE, presented data at a meeting of the Asian Network for the Rights of Occupational and Environmental Victims (ANROEV), about applications and approval rates for cerebrovascular and cardiovascular occupational disease claims. In 2014, there were 763 applications, of which 277 were approved (approval rate: 36%). By 2021, after the law’s enactment, there were 753 applications, but only 172 approvals (23%), indicating a decrease in approval rates. Meanwhile, overwork-related suicides—deaths by suicide resulting from work stress such as excessive workload, performance pressure, or workplace harassment—did not show a decrease in occupational disease applications or approvals after the law’s implementation. Regarding this trend, Professor Kenichi Kuroda of Meiji University pointed out that corporate efforts to comply with the law and implement preventive measures remain grossly insufficient, with companies prioritizing economic imperatives over legal compliance.[2]

A crucial factor in reducing cases of karoshi and overwork-related suicides is whether Japanese society and corporations genuinely recognize these issues as problems that must be prevented. However, many Japanese companies still appear reluctant to accept that reducing working hours and avoiding excessive workloads are part of corporate responsibility.

While companies have achieved reductions in the proportion of employees working long hours, they have failed to meet other key targets. The goal of raising the annual paid leave utilization rate to over 70% was not achieved, standing at only 56% in 2020. Furthermore, although the work-interval system—which ensures rest periods between workdays—was made a required effort under the “Work Style Reform” legislation, its implementation rate remained at just 4.2%.[3]

▲Source: Ministry of Health, Labour and Welfare, White Paper on the Prevention of Karoshi (2018), as cited in footnote 3.

Lessons from Ten Years of Japan’s Karoshi Prevention Law

On September 6–7, 2024, the Society for the Prevention of Karoshi held its annual conference in Kyoto, marking the tenth anniversary of Japan’s Karoshi Prevention Law. Presenters and discussants reflected on the achievements and limitations of the law, pointing out several persistent challenges in its implementation.

The discussion highlighted that the number of occupational accident applications and approvals related to karoshi remains low, with particularly low recognition rates among female workers. In addition, new forms of labor, such as freelance and platform work, remain excluded from the law’s protection. Participants also criticized the Ministry of Health, Labour and Welfare for its reluctance to recognize actual working hours, including overtime, due to concerns that such recognition could negatively affect corporate performance statistics.

Although the Power Harassment Prevention Act[4] has been in effect since 2020, the conference noted that effective supervision and enforcement are still lacking.

Emiko Teranishi, representing the Families of Karoshi Victims Association, stated, “Even if it takes years to gain official recognition and win in court, the person who died will never return.” Her words conveyed the deep pain of bereaved families who, after losing loved ones to excessive working hours and job-related stress, must endure long legal battles for recognition.

Ultimately, the conference underscored that preventing karoshi and overwork-related suicides must remain a top priority. The most important lesson from ten years of Japan’s Karoshi Prevention Law is that legislation alone cannot solve the problem. Despite strong public support when the law was enacted, karoshi has not disappeared from Japan. Real progress requires ensuring workers’ labor rights within companies and enforcing labor time regulations not for corporate flexibility but for the protection of workers’ health and dignity.

References:

[1] Lee SH (2018) 일본은 시간외근무 월45시간 넘으면 처벌, Japan to Penalize Companies for Overtime Exceeding 45 Hours per Month, Hankyoreh, July 15, 2018. https://www.hani.co.kr/arti/economy/economy_ general/853310.html

[2] Kuroda K (2021) The Significance and Challenges of the Act on Promotion of Preventive Measures against Karoshi, and Other Deaths and an Outline of Preventive Measures, Journal of the Society for the Prevention of Karoshi, No. 2, Meiji University, Professor Emeritus. 過労死等防止対策推進法と防止対策大綱の意義と課題. 黒田 兼一 (明治大学名誉教授). 過労死防止学会誌 第２号 (2021年度)

[3] Kuroda K (2021) The Significance and Challenges of the Act on Promotion of Preventive Measures against Karoshi, and Other Deaths and an Outline of Preventive Measures, Journal of the Society for the Prevention of Karoshi, No. 2, Meiji University, Professor Emeritus.過労死等防止対策推進法と防止対策大綱の意義と課題. 黒田 兼一 (明治大学名誉教授). 過労死防止学会誌 第２号 (2021年度)

[4] The term “power harassment”—a combination of power and harassment—refers to acts committed in the workplace by taking advantage of one’s superior position or authority, or dominance in workplace relationships, that exceed the appropriate scope of work, causing mental or physical suffering to others or deteriorating the work environment.