Sia's eldest half-brother. His posthumous title is Crown Prince Seongwon. He was born to Queen Seonghyeon, who was the Crown Princess. He was the royal grandson and the Crown Prince from birth. He has a gentle nature and cherishes all his siblings. He embraces his younger brother, Grand Prince Yeongwon, and his cute youngest sister, Sia. He is a magnanimous man who even tries to embrace the wild and reckless Prince Gyeongeon. His name is Hye. When Sia asked for Grand Prince Yeongwon's name, he told her his own name as well. At the time Sia is 6 years old, he is 20 years old and is referred to as Crown Prince Seongwon. Later, he leaves for Gangwon-do with the King for military training. He received a ring from his royal father, which the King had given to Hye's biological mother when she was Crown Princess, and he entrusts it to Sia right before leaving. However, the only thing that returns is the news of Hye's death. Yet, in the latter half of the story, it is revealed that he is actually alive. He had wanted to abandon everything and run away from an early age, so when a tiger attack occurred, he switched the corpse and went into hiding. The King checked the body himself and knew it was a fake, but knowing that Hye had fled, he pretended not to notice. Eventually, the truth that he is alive comes to light, causing various turmoils including a rebellion, but after several incidents, he passes the Crown Prince position to Hwa and leaves again.

Sia's half-brother. His title is Prince Gyeongwon. He is the son of Seon-bin, a concubine of the King. He follows his older half-brother, the Crown Prince, well and takes good care of his younger half-sister, Sia. His title as a Grand Prince is Grand Prince Yeongwon. After his older brother, the Crown Prince, dies in a tiger attack and Sia's biological mother, Suk-ui, also dies along with the royal fetus in her womb, Hwa, with a troubled mind, is looking through books when he hears that his younger sister Sia has visited his quarters, and he lets her in. While Sia was hovering between life and death, he was invested as the Crown Prince. He ate the dried persimmons a long time after Crown Prince Seongwon and Suk-ui died.

Prince Gyeongeon. He has a bad personality.

The biological father of Sia, Hye, Hwa, and Su.

Formerly Seon-bin. Lee Hwa's biological mother.

Prince Gyeongeon's biological mother. She has a bad personality. After Crown Prince Seongwon and Suk-ui die, she tries to feed Sia poisoned dried persimmons.

Her Royal Highness the Queen Dowager.

Sia's biological mother.