The encounters are sponsored by the government, which is seeking to tackle the widespread phenomenon of excessive working hours in Japan.

"My son had a strong sense of responsibility and worked past midnight for half of each month. He once worked for 37 hours without a rest," Michiyo Nishigaki said of her son, a system engineer at a Kanagawa Prefecture IT company who died in January 2006 at the age of 27 after overdosing on an antidepressant.

"Why did he have to die so young?" asked Nishigaki from the western city of Kobe.

The issue of overwork came under a renewed spotlight after a 24-year-old employee of Japan's largest advertizing agency, Dentsu Inc., committed suicide due to overwork in December 2015.

In September last year, Tokyo's labor standards inspection office recognized Matsuri Takahashi's suicide as a case of death from overwork, after finding that she had worked 105 hours per month of overtime -- well over the 70-hour limit set in a labor-management agreement.

The suicide of Takahashi cast light on the nation's widespread corporate culture of forcing employees to demonstrate loyalty by working long hours even at the risk of their lives, critics say.

Read also: Japan wants its overworked citizens to start weekends early

Under a law put into effect in 2014, the state is responsible for crafting measures to prevent overwork-related deaths and suicides. As part of its steps, the Ministry of Health, Labor and Welfare started last September inviting bereaved families and lawyers to share their experiences mainly with junior and senior high school students.

By March this year, the labor ministry had conducted a total of 87 such sessions at schools across Japan and plans to hold about 200 during the current fiscal year through March 2018.

"Telling young people what happened to my son is painful for me. But I'd like to tell them how meaningless it would be for workers to work at the expense of their lives," said Nishigaki, who has been speaking mainly at schools in the Kansai region centering on Osaka.

In fiscal 2015, the labor ministry recognized 472 people as suffering depression and other mental illnesses as a result of work-induced stress, qualifying them for government benefits.

Of the total, workers in their 20s and 30s accounted for 18 percent and 29 percent, respectively.

In the wake of a chronic manpower shortage, businesses tend to assign key tasks to young employees, even those fresh out of college, putting them in stressful work situations.

"Young workers should know before they enter the workforce how to protect themselves if they are forced to work under severe conditions," said lawyer Hiroshi Kawahito, who represents the family of Matsuri Takahashi.

Read also: How Japan's overwork culture leads to 'karoshi'

In early February, lawyer Toshimasa Yamashita visited Kaijo Junior High School in Tokyo to teach its students how to cope with work-related problems they may encounter in the future.

Yamashita asked about 30 students who attended his class how many hours a day employees are allowed to work under Japanese law.

Most students answered correctly, citing eight hours as mandatory daily working hours.

However, they could not answer when asked how many hours of overwork could affect a worker's health.

Yamashita explained that the government sees monthly overtime reaching 80 hours as possibly resulting in serious health problems.

The lawyer then said, "Do you know how many hours your parents work everyday?"

One male student in his senior year answered, "My father often comes home after 10 p.m. Although he doesn't look so exhausted, he may only try not to look so."