In Japan, excessive overtime work could lead to a presumed cause of death. Lots of workers have logged very high overtime hours. Families no longer accept compensation as the end of the matter and have started taking employers to court instead. These cases have started to decide what a company must know about its staff hours, and what it must do once it knows.
Definition of Karoshi in Legal Terms
Since 1980, there has been a term called ‘karoshi’ (death from overwork) used to describe what happens when workers die due to overwork. The Japanese government has a loose measure of whether overtime contributes to worker fatalities; if the worker exceeds 80 hours per month of overtime across multiple months, or if the worker works 100+ hours in one month of overtime, the investigator assumes that the job may have caused a fatal heart attack, stroke, or suicide.
Mostly, families file for workers’ compensation first. When the claim is recognized by the authorities, the survivors are eligible for survivor benefits, but this does not require the employer to take responsibility for anything. The company does not have to pay the family anything directly and does not admit fault.
Transition from Workers’ Compensation Claim to Litigation
This is why some families pursue additional action. According to the Labor Contracts Act, employers have an obligation to protect the safety and health of their workers. If a family can prove that the employer knowingly ignored obvious signs that could have prevented the worker from becoming ill or dying prematurely, then they may be able to pursue a wrongful death lawsuits against the employer.
English-language media often refer to these types of wrongful death actions as such; however, Japanese courts view them as breaches of the employer's obligations to ensure their workers’ safety. Damages awarded in successful claims can exceed tens of millions of yen.
Evidence supporting these claims is typically mundane. Attorneys build these cases through evidence such as data showing when employees log onto computers, swipe badges to enter buildings, and send email messages to supervisors at 3 am to ask when they should come back to work.
The Dentsu Decision
In 2017, a Tokyo District Court imposed a 500,000 Yen fine on a company for violating labor laws after an employee died after working overtime of more than 100 hours in a month. While the fine was less than what many employees receive as their monthly salary, the press coverage surrounding the decision was much greater. The president of the company resigned shortly after the announcement, and the company began turning off the lights in offices at 10 pm. The employee’s mother also became a well-known advocate for workers' rights.
Changes Resulting from Overtime Limits
Japan passed legislation in 2019 requiring employers to establish caps on overtime. Specifically, the cap established limits of not more than 45 hours of overtime per month and 360 hours of overtime per year. Special circumstances permit overtime of up to 100 hours per month for certain individuals, such as medical professionals. Current reviews are in place to amend labor guidelines even further to focus on employees health.
Where Japan Currently Stands
Claims related to karoshi typically follow fatalities by a number of years. The impact of the 2019 changes will not be evident in court decisions for several years. Given past patterns, initial judgments based on the new overtime cap will depend on these questions: Did employers know how many actual hours their employees were working? If they did, what was done about it?














