Strong Female Lead

She was introduced with a  bang, but unlike the fate of many female leads, she never loses that badass quality. She's a balanced character. Equal amounts capable and emotional; Ha Jae was not only very mature and rational throughout most of the series, but she was also very gentle and nurturing towards Bong Sang Pil (ML). She's also someone who's confident in her knowledge and ability, but who's also humble enough to accept she doesn't have all the answers. When Bong  Sang Pil puts her knowledge to the test, she's open-minded enough to tackle every uncomfortable issue head-on, unwilling to compromise the truth for the sake of convenience.

Though there are some inconsistencies in her character and her personality falls a bit flat, she's one of the most active female protagonists in Kdrama land and is integral to the story. From a weak woman clinging to her life, Byun Ji Suk grows into her power as the drama progresses. It's worth noting she remains the protagonist throughout the series, rather than fall into a supporting role to the male lead (which usually happens).

Despite her tragic backstory, Gil Nak Won is a strong character. Not because she got over her past, but because she's able to face her present while accepting what happened. Her strength is quiet and subtle; allowing her actions to silently showcase her defiance. She never once runs from her problems but faces them head-on. Because of the nature of the story, Na Moo's (ML) side of the story was more intense, but she is without a doubt one of the strongest female leads I've seen in Kdramas so far.

In addition, we have Ok Hee, one of the strongest support female character (stronger even than the FL) and probably the best K-drama Mom!