Here in Korea, office workers have a 40 hour workweek (anything over that is considered overtime in most industries) but usually stay 15-20 hours longer each week because it's considered selfish and rude to leave before your boss/manager/whatever cantankerous old fart is in charge does, so everyone just pads out their time with bullshit and sits at their desks pretending to be busy until 9-12pm every night (many people come into work at 9 but don't even start working until the afternoon because they know they have to stay late). Sometimes people even come in on weekends and do this to build up cred.

Of course sometimes people are legitimately busy and have to stay late but I'd say about 60-80% of the time just they're just doing it because of peer pressure/the office culture because it's what they have to endure if they want to be promoted.

The one way you can tell it's complete BS is because you're not allowed to come in early or on the weekend to build up unpaid overtime cred, you have to do it at night when everyone else does so people can see you. Because it's all about appearances and nothing else.

It's sickening, especially because it's UNPAID overtime. Drives me up the fucking wall. Everyone is just throwing all their free time away for no reason. What's worse is that the young generation isn't exactly sticking up to the old ways because they've been conditioned their entire lives to be spineless and obedient. Japan is the same apparently but I haven't experienced Japanese office culture first hand so I can't comment on it.

I work in this kind of environment and do a wee bit of unpaid overtime to get people off my back but I'll never sacrifice my evenings on the altar of appearances just because. Luckily I'm a foreigner so they cut me a bit of slack.