Supporting
Kang Hoon as Ha Jong-ho
Oh In-kyung's childhood friend and strong supporter, who has feelings for her.
Cho Seung-yeon as Jo Wan-gyu
Director of OBN Social Department.
Gong Min-jeung as Jang Ma-ri
A reporter at OBN news agency.
Kim Mi-sook as Oh Hye-seok
Great-aunt of the three sisters.
Park Ji-young as Ahn Hee-yeon
Mother of the three sisters.
Um Ki-joon as Park Jae-sang
A lawyer and rookie politician who gets involved with the three sisters.
Uhm Ji-won as Won Sang-ah
General's daughter, politician's wife and Director of the Museum of Art. Her relationship with the three sisters begins when Sang-ah's daughter Hyorin becomes involved with Oh In-hye.
Jeon Chae-eun as Park Hyo-rin
Park Jae-sang and Won Sang-ah's daughter, and Oh In-hye's best friend.
Lee Do-yeop as Won Ki-seon
Security Commander in the 1980s and Won Sang-ah's father.
Lee Min-woo as Won Sang-woo
Won Ki-seon's son and Won Sang-ah's older brother. He was a son who didn't matter to his father.
Wi Ha-joon as Choi Do-il
He graduated from a prestigious university and becomes involved with Oh In-ju. He is a mysterious character whose true allegiance is unclear. His father was part of the Jeongran Society, but was murdered for betraying them; his mother was framed for his father's death. Though Do-il's true allegiance is unclear for most of the part of the series, he is shown to be protective of In-ju.
Park Bo-kyung as Go Soo-im
Park Jae-sang's right-hand assistant.
Jang Gwang as Jang Sa-pyoung
Principal of Wonryong School.