She falls for him but he is already in love with someone else. Eventually they get together, but is a slow-burn. It can also be the other way around (he falls first but she loves someone else)
Examples:
BoF/Hana yori dango/Meteor garden. He falls for her but she is in love with his best friend. Eventually they get together, but it takes time (these are my all time fave dramas).
Bring it on ghost. I just finished this drama and LOVED IT. He has a crush on some girl at first. FML chases after him and he's annoyed by her at first but when she's not around he misses her. When they finally get together they are the cutest couple. PLUS is Taecyeon and I love him.
Seoyeong ,my daughter (Secondary couple Sangwoo and Hojung). Hojoung falls for him at first sight but he doesn't even care and it's kind of a jerk at first. He falls for some other girl and gets together with her but eventually break up and marries Hojoung without loving her but with time starts caring for her and falls in love. This is one of my favorite couples in korean dramas. ❤️
My golden life (Secondary couple Jisoo and Hyuk). Cute, cute, cute, cute. Jisoo is so in love with him but he doesn't even like her because of some stupid prejudice and he is in love with her sister. Later on he gets to really know her and falls for her.
Weightlifting Fairy Kim Bok-joo. He likes her. She is in love with his brother. (He even help her get together with the brother). I loved this drama so much because they developed a true friendship before realizing their feelings for each other.
Strong Woman Do Bong Soon. He is in love with her but she is in love with her friend. This was a very cute drama.
Fated to love you. (Both versions)
Güneşi Beklerken (Turkish drama). They hate each other so much but with time he falls head over heels for her but she is already dating his best friend. It takes a while for them to get together.
My girlfriend is a gumiho
Gu Family Book
Oh my ghost
Hope you can help me. Thank you. ☺️
Stay safe.