East Asian cultures are very attentive to hierarchy and status levels. It is very usual for a boss to use the casual form for their employees. Even if they are older!
I can only talk about Korea, because I’m not really familiar with Chinese and Japanese culture, but I know that the concept is very similar in all of them.
Levels of politeness in speech - Korean
So it seems that there are many levels of politeness.
- Casual, first name: only with children, close friends of the same age, younger siblings and sometimes older siblings in modern families
- Casual, full name: from superior to inferior at work, from rich man to poor socially low person. OR if you want purposefully to be rude. A policeman to a criminal, a criminal to his captive, people having a nasty fight.
- Polite form (in Korean, it ends with -yo), full name with ending -ssi in Korean (it means Mr/Ms/Miss): Friends and colleagues of similar age group. Also for one’s spouse, especially women to their husband. Often the husband addresses the wife casually but she addresses him with the polite form.
- Polite form (in Korean, it ends with -yo), no name but only job designation: Higher rank colleagues, acquaintances, the person you’re in love with but haven’t married yet (yes, you may have kissed, you may date, but you still call her “Director Choi”).
- Formal form (in Korean it ends in -mnida), no name, only job designation. Higher-ups at work, strangers, older people such as your parents’ friends.
- Super-formal form (in Korean it ends in -mnida but there is an additional insert in the middle of the verb, and the suffix -keso after the appellation): to people you want to show lots of respect to, like grandparents, the president of the company etc. For this form, there are also some alternative verbs, for instance to eat, to sleep, it’s a wholly different verb than the usual. Long list to learn, I hated this.
And I may be forgetting some, since all these have their nuances.
What is the situation in my language?
I work with Italian with Greek.
In Greek we have two forms, casual and polite. Period.
In Italy we used to have three styles, in rising formality order.:
tu - in Roman times, there was only this. You said “tu” even to the Emperor. Nowadays it’s the most casual address.
voi - came with the French, it’s like the plural of you, and was used until after WW2, when it was dropped because Mussolini favoured it. But my grandma in the 70s also used it when she spoke to the maid and the greengrocer, and many old people in the South still use it. It’s dying, though. We use it only for historical times.
lei - came with the Spaniards (translation of "usted’). It means “she”. Strangely enough, it’s used to address a person directly, even if it’s a man. Because it implies “Your Highness” where highness is feminine. You speak to your teacher to ask him something and you say to him “She thinks that my work is good?” Yes, I know, it’s mind-bogglingly absurd. For many centuries, it was used alongside the “voi”. Voi was for ordinary respect, and “lei” was for very high-up individuals like a governor or higher.
Nowadays that “voi” was buried, “lei” is used in all instances where you don’t use “tu”. But “tu” is gaining ground, shop vendors will address casually even a mature client. I snap at them when they do so, did we know each other as children? They are young enough to be my children or even grandchildren, so what’s with the lack of respect?
What I do for dramas?
- If it’s historical, only “tu” for peasants and commoners and “voi” for nobles.
- If it’s modern, I try to listen to the Korean and I follow - up to where it’s logical.
This means I do make the bosses address their subordinates casually, although it would NEVER be done in Italy. But it’s part of understanding the Korean culture, which is NOT like ours in many ways. If you start adapting it to European normalcy, then you have some behaviours which don’t make any sense for a European (the blind obedience to parents for instance, the stigma for single mothers etc etc) and then it’s a great shock for which the audience is unprepared.
For parents, it’s a great temptation to use “voi”, but Italian people scratch their heads a little. If they know the Korean conventions they will understand why I’m using it, but many don’t agree.
In “Memory”, the male lead’s wives (ex and present) both addressed him with the polite form, and he addressed them casually. His children addressed him with the polite form. All this I changed to casually, as if it were a European family. I felt uneasy doing this, but I felt it was inevitable.
I have a completely arbitrary rule that when the couple kisses and starts going steady, I switch to “tu”, although the Korean doesn’t. Two people who may have had sex addressing each other formally - it would be too ridiculous for any Western viewer.
In “Encounter”, the two lovebirds start dating mid-series, but he goes on to call her Director. They sometimes drop a line or two of banmal in very convivial moments, but they only start speaking casually to each other only on the last minutes of the last episode.