It is famous that Japanese work too much.
After decades, it is getting better but still Japanese work too hard comparing with other countries.
Checking job ads, the over-time hours says 10-20 hours but actually it is 30 hours at average.
The middle-level executive experience more hard condition, attending a meeting on Saturday and working until 10-11pm on working days.
One of the reasons that Japanese work so hard is that there is implicit thinking that staying at company means working hard.
Although the number of the companies which think that finishing jobs in nine-to-five means doing job in an effective ways is increasing, there are still death of overwork.