Unfortunately it can be so easy to not know your own value, but it's very dangerous to find that value in other people's opinions/affection for you.
Self image is a big thing for my leads in "Damsel in the Red Dress" and "Hushabye Prince."
Despite being very handsome, Kattar feels worthless because he's paralyzed, and thinks that means he doesn't deserve to be loved by his best friend, because there's nothing he can do to care for her.
His bff (Alicia) spent her life feeling like a hand-me-down because after her parent's divorce, she was living in the care of a poor aunt, who couldn't afford to give her much of anything. Even though she doesn't completely think she's ugly, the scars covering her body are a huge struggle for her to deal with and not let them ruin her self esteem.
for the leads in "Hushabye Prince" Kimberly doesn't look like 90% of people either, being a black girl with blond hair and green eyes, and also having the habit of signing when she spoke as the hearing child of deaf parents. She's never really fit in, and that caused her to try to do whatever it would take to get people to like her.
And Jinwoo might be the saddest of them all. It's doubtful that he realizes how handsome he is, all he knows is that people have always been afraid or made uncomfortable by him, and that's obviously no way for anyone to grow up.