Recently, the Nagoya District Court in Japan, accepted Hiroko Uchino's claim that her husband, Kenichi, a third-generation Toyota employee, was a victim of karoshi when he died in 2002 at the age of 30. He collapsed at 4am at work, having put in more than 80 hours of overtime each month for six months before his death. The ruling is important because it may increase the pressure on companies to treat “free overtime” (work that an employee is obliged to perform but not paid for) as paid work. That would send shockwaves through corporate Japan, where long, long hours are the norm.

Tallies show that one in three men aged 30 to 40 works over 60 hours a week. Half say they get no overtime. Factory workers arrive early and stay late, without pay. Training during weekends may be uncompensated.

The effect of the ruling remains to be seen.