The youngest daughter of Emperor Gojong and the half-sister of Emperor Sunjong, Prince Uichin, and Prince Yeongchin. She is the last princess of the Korean Empire. As the only daughter, she grew up receiving much love from Gojong, but after the country was lost, she was sent to Japan and married So Takeyuki. In the original history, her schizophrenia worsened after giving birth to her daughter Masae. Because of this, she suffered from hallucinations, delusions, disorganized speech and thought, and a severe decrease in emotion and motivation. After the fall of Japan, she was admitted to a mental hospital and returned to Korea in 1962. Perhaps due to her illness, she has a distant relationship with her daughter, So Masae.

The 10th generation head and final lord of the Count So family, as well as an English scholar, poet, author, and professor of literature. An elite student who graduated from prestigious schools, he married Princess Deokhye. He is a devoted husband and possesses handsome features. He took full responsibility for childcare and often attended Joseon royal events with Masae. In the original history, after Masae was born and Deokhye's mental illness worsened, he sent her to a mental hospital following Japan's defeat. Struggling to manage the household after being demoted to commoner status when the peerage was abolished, he divorced her. He later remarried Katsumura Yoshie and had two sons, Tatsuhito and Nakamasa, and a daughter, Waki. He later traveled to Korea wanting to see Deokhye, but died without being able to meet her.