I haven't watch any dramas with depicted racism. Maybe because it's taboo like people above said or bad adversement for their entertainment dramas.
But I know that it exists in Asia and everywhere.
We have different kind of racisms : the one against foreigners, the one against people with a different skin color, the one against people with another religion, etc. This type of differences and some others can be subject to racism.
I saw a documentary a few years ago about Asian people who lived in Western countries and then came back to their mainland. What the woman was saying was : "You see, I'm like a banana. Yellow outside but white inside. I'm not recognized as a citizen in the country I'm living or I don't feel at home in the country I was raised and in the country of my ancestors, I'm not recognized as one neither." (the banana metaphor and the feelings are exact but the words I used are not the way she said it but it's the same meaning).
What she meant was people from her mainland (in Asia) don't see her as Asian because she was taught a different culture, she has different values and even in her behaviour, the way she talks, her different upbringing from other Asian kids is showing.
So even if she has the looks of an Asian, their physical characters (yellow peel of the banana), she's different inside from Asian people raised in Asia (white : westerners).
What was interesting was people don't treat her the same way (of course because she's different).
And that to the fundamental questions : Where's my home ? What's my identity ?
She met an identity crisis because she thought of finding her home and identity going back in Asia but she was met with another kind of "racism".
Some older ones don't like some westerners values or behaviour. You'll be critiziced, you'll be ignored, you'll be called with names, you'll be treated differently than a lambda Asian etc.
It's the feelings of some Asian people not every Asian living abroad and not everyone's reaction.
In the reality show My Neighbor, Charles (foreigners living in South Korea), I remember watching an episode where young children were afraid of an African dancer because they never saw someone with dark skin and he was in his tribal costume so they were afraid because of differences and what they heard about, and in their own reality they can compare him with "demon" because of the skin color and clothes. They were whispering between themselves "He's all black !" and they didn't dare to approach him. But after dancing and the man was smiling and nice with children, playing and all, children changed their behaviour little by little. Instead of feeling fear, they were laughing and having a good time. At the end, they were becoming more friendly with the man.
In the same show, there was an episode with one Muslim woman and her children. She was wearing the hijab and she was teaching the prayers to her daughter who was young so she wasn't wearing a hijab outdoors. The young girl didn't want to wear a hijab outdoors because she was afraid to be different from other children and how people will react to it. Maybe other children will laugh at her or exclude her because she's different, they might think that she's weird when she will do her prayers. And she was afraid to lose her friends (parents can tell to their children not to hang out with her, parental influence).
And her mother told her something like : "You can explain them that it's because of your religion". Etc I dont really remember what she told her daughter.
People are influenced by what they are told from teachers, family, friends. We are not born knowing what racism is. People are not born racist but they can become racists. Humans created it.