The main lead (who loves second female lead) hurts the female lead who loves her a lot. Let it be little light ...may it not be grey or dark drama
Please reply me
Another Miss Oh I think this suit what you look for
Girls' Generation 1979 Female Lead end up with SML but hurted by the other guy because he is in love with her friend
A Gentleman's Dignity There is no second female lead but ML hurts FL's feeling with another woman in first eps
She was Pretty There is some misunderstandings but ML thinks he likes FL's best friend
Hot Young Bloods It's a movie but you can look at it if you like
A Korean Odyssey
Last Cinderella but with a twist: the second female lead is his sister.
Loving never forgetting.
Fated to Love You
I Have A Lover
Que Sera, Sera
And a lot of thai dramas like: Sud Sai Pan, Sawan Biang (THE worst), Ngao Asoke.
Full House
Maybe...
.. and mostly romcom and light dramas:
Anothdt miss oh fits this perfectly! Omg its sooo good.