Lee Hae-in Starring Jeon Hye-yeon

Hae-in is the daughter of Lee Soon-young and Kang Chi-hwan. She is alive thanks to Soon-young’s sacrifice. But she grows up trusting and depending on Lee-chang, her stepfather. She is warm and considerate, but doesn’t fully open up to others or let her weaknesses show. It may be because she grew up at an orphanage, but she tries to keep a certain distance from others to protect herself. She tries twice as hard as others, but rarely trusts others fully. There are only three people in this world that she loves and trusts with her life. Jung-im, Lee-chang and Jin-woo.

Ha Jin-woo Starring Seo Han-gyeol

The son of Ha Yoon-mo, the CEO of Sunjoo Fashion, he is a major in business administration, but is a free soul that does things like directing plays. Jin-woo’s father expresses his love endlessly worried he’d also lose his son. He even tries to fill the empty space of Jin-woo’s mother by marrying the woman Mi-gang introduces him to. None of it helps Jin-woo change, but he starts talking and laughing again when he meets Hae-in, who is from an orphanage, and they build memories together. When Jin-woo expresses his wishes of having Hae-in as his sister, his father tries to adopt her, but fails. She leaves a strong impression and sadly disappears.

Kang Se-na Starring Jeong Woo-yeon

Se-na is Mi-gang’s daughter. Her birth father is Lee-chang, but she is born and raised as Chi-hwan’s daughter. Being gorgeous and part of the upper class, she always stands out and is the center of attention. Mi-gang stands up for her saying it’s a characteristic of people that are wealthy, but Se-na is stressed and discontent about letting her father down. Her goal is to become the perfect and trustworthy successor to her father. The only time Se-na can truly smile is when she is with Jin-woo, whom she likes.
But when she sees how Jin-woo treats Hae-in, she realizes she was nothing more than a sister to him.

Moon Do-hyun Starring Jin Ju-hyung

He is the posthumous son of Oh Hwa-soon, the live-in help of the Jeon Sang-cheol family. He has a fierce spirit that helps him achieve whatever goal he has. He grew up experiencing social class inequality at first hand. He hated living at an annex that was barely more than a dog house in a corner of a large house, and watching his mother rush over whenever someone called, while his uncle was the driver. He is interested in Se-na, but knows he can never be like Jin-woo. So he studies like his life depends on it. He passes the bar and becomes a prosecutor.