When she was younger, the First Princess had long wavy hair and a pronounced chiseled face. She also had long eyelashes and thin eyebrows. Notably, she had long dark-painted fingernails.
Like her siblings, she is greedy and slow-witted unlike her half-sister Rei, who is exceptional and intelligent. Because of this, she and her siblings became jealous of her and Yeong Bi, having become the objects of favor of the previous king. She is also cunning, having thought of a way to slowly kill Yeong Bi without leaving evidence.
She is the eldest sister among Jang Ryun's first children with his queen consort. After a year-long inspection of the country, her father returned with a commoner named Yeong Bi with whom he had a daughter, Jang Rei. As the latter grew up, she earned the favor of their father but also of the elder children's envy and bitterness.
As a result, together with her siblings, the First Princess would bully and pick on Rei, particularly excluding her from royal occasions because she is a daughter of a commoner. In general, she would view Rei to be different from her other siblings, claiming her to be of lowly birth.
After the death of her father, her brother ascends to the throne. They found out about the previous king's entitlement of one-third of Seo Seo to Rei, much to the First Prince's fury. The First Princess suggested disposing Rei and Yeong Bi, especially without their father to protect them. In the first place, she had been poisoning Yeong Bi's teas ever since Jang Ryun's death. Eventually, Yeong Bi died, leaving Rei completely orphaned.
|Characters of Twelve Nights|
|Royal Family||Ahn Young • Hyun Bin • Jin Hyul • Jin Jeok • Jin Won • Unnamed Baby Prince • Unnamed Baby Princess • Yi Hwi • Yi Sae Gi • Yoon Yeon Lee|
|Ministers||Hwang Se Hyung • Kim Hak Gyu • Sa Hwa Hyeon • Seo In Seon Woo • Wi Ji Hyun • Yi Ha • Yoo Ja Gyeom|
|Bi Yeong Pal Mu||Baek Ah • Baek Ju • Baek Lin • Baek Ryung • Baek Sa • Heuk Rang|
|Bi Yeong Ship Mu||Baek Ho • Baek Yoo Shin • Gil Mu Jin • Yi Ha|
|Deung Ha Bul Myung||Baek Ho • Crimson Moon • Gil Mu Jin • Nabi • Seol Hwa • Seo In Seon Woo • Wol Young Hwa • Yi Hwi • Yi Jeok|
|Yu Hyang Ru||Nabi • Wol Young Hwa • Yi Jeok|
|Others||Chung • Hwang Se Ryeon • Hyun • Ma Mi Song • Nam Yang Heon • Sori • Woon • Yi Ha's Wife • Yoo Dan Ah • Yoo Dan Ah's Mother|
|Royal Family||First Prince • First Princess • Jang Rei • Jang Rok Ha • Jang Ryun • Second Princess • Three Wives of Jang Ryun • Unnamed Baby Prince • Unnamed Baby Princess • Yeong Bi|
|Others||Gwak Ji Ryeon • Meng Gyeom|