A drama where the female main character falls in love with the male main character and knows that she shouldn't. 

Any country is good. :) thank you for all the suggestions. 

Hmmm I hear your voice !! xD
Hotel King (Kdrama) - but its the other way around, the male lead thinks he might be related to the female lead but still falls for her, then later they find out he isn't and they get together xD
Youre beautiful
Rooftop Prince
Shining Inheritance
Goong
Secret
Gu Family Book
:)
& Rich Man, Poor Woman <3
Secret Love Affair (kdrama)