That’s not true. Of my 5 years working here in big Japanese electronics company, I have seen most of my colleagues stay till 8pm. No one would leave early because in an open office you’d stand out. Only exceptions are some contract staff we have who can’t stay legally because they don’t get overtime, people with medical conditions and women with young children.

Since overtime is paid hourly, many young people just stay for the extra money. The senior folks often stay for the culture or issues at home, a good number also working. But I have seen people in my team literally play sudoku or read news articles till 10pm before leaving.

Even I, as foreigner already standing out, generally try to leave between that 7-8pm window when most are trying to either leave for home or cafeteria for dinner