He was a 20-year-old high school graduate, toiling at a chocolate factory for Japanese firm Goncharoff where he was derided as "worthless" and taunted for making chocolates "as good as cow feed".
His superiors allegedly poured scorn on Mr Hayato Maeda when he decided to quit, after clocking between 81 and 105 hours of overtime each month between September and November 2015.
Using the derogatory form of the word "you" in Japanese, they are alleged to have said: "You only have high school education. Nobody will want to hire you."
Having endured harsh rebukes from his superiors and chronically long hours since he joined the company in 2014, he became severely depressed by December 2015.
At the end of his tether, the young man leapt in front of an oncoming train in Kobe in June 2016.
Mr Maeda's tragic case, which came to light on Thursday, has officially been recognised by the government as karoshi (excessive overtime) and pawahara (power harassment), terms which have wormed their way into the Japanese workplace lingo.
"I just want to tell my son, 'You are not worthless'," his mother Kazumi Maeda, 44, said at a news conference. "He was gradually being driven to his death."
Rather than accepting wrongdoing, a spokesman for Goncharoff has disputed the government's findings. He told the domestic media: "We see no basis in the claim and as such do not recognise there was excessive overwork or power harassment."
The government has noted that Goncharoff practised what is known in Japan as "service overtime" - or hours that are off the books. Mr Maeda was recognised to have worked only a total of 88 hours of overtime in the three months preceding his clinically diagnosed depression.
Japan might have passed work-style reform laws in Parliament late last month, but it remains unclear how far they will go to protect employees.
In the latest statistics released by the Ministry of Health, Labour and Welfare (MHLW) on Friday, there were 840 requests for compensation for brain and heart diseases related to overwork last year, an increase of 15 cases from 2016.
More than a quarter of the cases - 253 - were deemed to be due to overwork, of which there were 92 deaths. There were another 1,732 requests for compensation for mental health - including depression - cases related to overwork last year, an increase of 146 from 2016.
Of these, there were 221 suicides and attempted suicides, an increase of 23 cases from the year before, MHLW data showed.
The new work-style reform laws remain contentious, though, with critics saying they inadvertently sanction overwork by putting an arbitrary 100-hour cap on overtime per month, up to 720 hours a year.
White-collar workers with annual incomes above 10.75 million yen (S$132,000) are also exempted from these limits, in what is intended to enable flexible working hours.
Sociologist Emi Kataoka of Komazawa University in Tokyo told The Sunday Times that it is deeply ingrained in some managers to prioritise profit above the human rights of their workers.
She said the new work-style reform law, intended to drive productivity, may backfire because of the "high possibility that workers will be at the brunt of stronger pressure and more harassment to raise their productivity".
She added: "It is also a reality, that there is no law to protect workers from power harassment."
