San, but very ambitious and can be somewhat shady. Hong is at times hungry for power and when he has it, he sometimes abuses it. He was also the main tutor who helped Dae-su when he was training for the military exam. Throughout the series, he was promoted to Chief Inspector, Chief of the Royal Guard, and Chief Secretary due to his skill at politics and investigation. His younger sister also became one of Jeongjo's concubines and Hong Guk-yeong hoped to have enhance his influence by being related to the King's future heir. However, his sister would die out of grief after a failed cover-up of a phantom pregnancy (due to potential scandal). Enraged over the fact that she died unforgiven by Queen Hyoui and her remark that he would have no influence over the next heir, he made a bargain with Queen Jeongsun to allow him to be the adoptive parent of a member of the royal family. In the end, he was exiled for trying to poison Queen Hyoui out of anger over his sister's death and to prevent his bargain from being exposed, for Queen Hyoui discovered it and threatened to tell King Jeongjo. He aborted the attempt after discovering that the King was taking her place at the food ceremony and tearfully confessed. He later died at peace due to health issues after being forgiven by the King. Jeong Yak-yong (played by Song Chang-eui) A scholar from the Confucian Academy and a member of the Namin Faction, he was initially unable to enter the court for three years. Later, after entering, he replaced Hong Guk-yeong as Yi San's closest adviser. While not as politically skilled as his predecessor, he is extremely innovative and is a talented inventor. As a skilled-albeit clumsy investigator, he is also aware of the flaws in the government and called for reforms. Yang Cho-bi (played by Lee Ip-sae) A damo at the Bureau of Painting. At first she was very rude to Song-yeon. But when she fell in love with Dae-su and discovered that Song-yeon was practically his sister, she became nicer to her. At first it was for Dae-su, but eventually she developed a real bond and friendship with Song-yeon. When Song-yeon became concubine to Jeongjo, Cho-bi was selected to be her lady-in-waiting, an attendant court lady of the 6th rank (in Joseon, all royalty, palace servants and government officials are