Dramas about Lost or separated brothers tropes , ML withSML or whatever

Handsome Siblings fits perfectly. The ML and SML are twins separated at birth and raised to be enemies by rival sects.

Dramas where it's one of the main focuses of the plot:

• Hello Monster

Dramas where it's present in the story, but might not qualify as one of the main focuses of the plot:

• Pinocchio
• Her Private Life
• Hi! School - Love On
• Hwarang