In japan, there is a strong pressure to not be the first one to leave the office (especially in small companies). Being a workaholic is considered good and being the one who works the longest carry a certain aura of prestige.... So the manager doesn't even really try to persuade you it's the environment around you, when it's officially time to leave for the day and every one around you continues working, it's hard to go back home and you even end up using an excuse like if it was somehow wrong to respect you working hours. Another thing, if you finish normally at 6pm, if the company organizes a dinner between coworker at an izakaya (a kind of pub), they usually plan to go around 8pm since everyone will still be working or busy at 6pm anyway...

On the flip side, a lot of smaller companies have rest areas and it's not really looked down (at least for programmers) to go and read the newspaper or a manga during working hours to decompress from a problem.