Dentsu’s president admitted at a court hearing on 22 September that the company had failed to act to rein in a culture of illegal overtime.
The case, which centres on the work-related suicide of a young employee, Matsuri Takahashi, in December 2015, is drawing to a close, with a ruling scheduled for 6 October.
Toshihiro Yamamoto, who replaced Tadashi Ishii as president in January 2017, apologised on behalf of the company to the deceased victim and her family. He said Dentsu had failed to fulfill its social responsibility, and vowed to ensure a similar incident does not happen again.
The victim’s mother, Yukimi Takahashi, reportedly expressed scepticism at the promise, noting at a press conference that Dentsu was aware it had an overwork problem before her daughter joined the company.
Others see the proceedings as cause for optimism. The open trial is highly unusual for a case relating to death from overwork, and observers have suggested that the legal system is making an example of Dentsu, taking into account the power it wields in Japanese society.
An editorial in The Mainichi newspaper said the trial sent "a strong message" to other companies that foster a culture of extreme overwork, and to society as a whole, which has only recently begun to seriously question the ethics of such practices.
Dentsu has introduced various measures to change its culture and aims to reduce working hours by 20% by 2019. Improbably given the notorious workloads, it has even reportedly floated the idea of three-day weekends, something that Yahoo Japan has also considered.
A version of this article was first published by Campaign Asia-Pacific