Simply, I'm sick of Cinderella stories. Why does the nobility always have to be the ml? And why does the fl have to be some random, ordinary girl who catches his eye? Of course, not all stories run this course, but it's still painfully common.
Are there any about a princess? Extra points if her love interest has a really humble background.
It doesn't need a happy ending, because when is there ever a happy ending between a princess who elopes with a nobody - although that could make an interesting story. Princess elopes with her love when they're young, impulsive and ignorant, experiences the harsh reality, regrets it, but needs to grow up and come to terms with her life decisions. Unfortunately, I don't think that exists.
Only one movie comes to mind - The Magician. It's Korean and about 2 hrs long. Here's the synopsis: A Princess in the Joseon Dynasty travels to the Qing Dynasty to marry. On the way there, she meets a young magician and falls in love with him. I thought it was a pretty good movie with a beautiful ending.
I mean, technically The Princess’s Man does fit this description. Neither of them start off as direct royalty but she ends up the crown princess and he ends up the opposite of where he started. So maybe the first few episodes won’t be exactly what you’re asking for but the rest of the drama will be, and the ending is neither too optimistic nor too pessimistic.