It is significant that the alleged violation of labor rules at Dentsu Inc. in connection with the 2015 suicide of an overworked employee will be tried in a regular court proceeding, instead of being given a summary court order for fines as sought by prosecutors. The high-profile case — involving the nation's leading advertising agency — can serve as a catalyst for enhanced efforts to end health-endangering overwork. The court needs to expose how the labor regulations were violated at Dentsu, and companies need to learn from the case and try to protect the health of their own workers.

Matsuri Takahashi, who joined Dentsu in April 2015, killed herself that December at age 24 by jumping from her condominium in Tokyo. It was later determined that she had been suffering from depression caused by overwork. Labor standards inspectors found out that she had worked 105 hours of overtime in a single month before developing the disorder. It was subsequently discovered that the company had its employees, including Takahashi, work more overtime than allowed under an agreement with its labor union. The closely watched case at the major company reignited calls to prevent karoshi (death from overwork) and drove the government to push for a legal cap on overtime hours.

Earlier this month, prosecutors summarily indicted Dentsu on charges of violating the Labor Standards Law but chose not to indict senior Dentsu officials, including Takahashi's superior, for their role in the violations on the grounds that their responsibility could not be deemed malicious. A summary indictment normally leads to closed-door, document-based proceedings, resulting in a summary court order for fines. However, the Tokyo Summary Court said such simplified proceedings would be "inadequate" for the Dentsu case and decided to put it to an open trial.