The most common trope that fits my request is rich man/poor woman. No to rich man/poor woman trope because alot of it is the same. Only if you can convince me there is actual plot/drama in it and not a rom com. I don't mind rich woman and poor man life styles.
Other examples would be the ML lives a gangster/thug/problematic life while the FL lives a carefree happy life(not as a cop that would lead her to the ML where she might have to arrest him). He lives in the countryside, she lives in the city. He lives with a uncaring family but she lives with a lively caring family. He lives as a loner but she lives with fun and friends. He lives a life struggling nothing good happens but she lives a life where everything good happens to her.
These are just some ideas I thought of but you can recommend Kdramas that don't fit what I listed but still fall into the opposite lifestyles idea. Less of a rom com and have a bit more plot/drama involved too.
Dramas that I dropped/no interest in that might fit into my idea are: Hometown Cha Cha, Descendants of the sun, Oh my venus, It's ok to not be ok.