October is the peak time for Red Kites, with 1940 counted on 7th, the highest daily total since records started.

Her employer only made the tragic case public this week, bowing to pressure from Sado's parents to take action to prevent a recurrence.

The case has highlighted the Japanese problem of "karoshi" - meaning death from overwork - and is an embarrassing revelation for NHK, which has campaigned against the nation's long-hours culture.

NHK's chief has pledged to improve work conditions at the broadcaster."We are sorry that we lost an excellent reporter and take seriously the fact that her death was recognised as work-related," President Ryoichi Ueda said Thursday."We will continue to work for reform in cooperation with her parents," he told reporters.

Every year in Japan, long working hours are blamed for dozens of deaths due to strokes, heart attacks and suicides.

Adverse publicity, some real action by the authorities, some exemplary fines, and the strictures of the new environment minister, have all also played a part.

But the LPO will be checking on the ground in 2018, just to be sure.

According to a government report on death from overwork released on Friday, there were 191 "karoshi" cases in the year ending March 2017.

The report also showed that 7.7 percent of employees in Japan regularly log more than 20 hours of overtime a week.

Labour minister Katsunobu Kato told reporters on Friday that the government will "do its best" to reduce the number of people who die from overwork to zero, according to NHK.