37 Princess Cheongin. She has sharply styled black hair, keen eyes, and wears a sophisticated two-piece suit. A key figure in diplomacy with cold logic and overwhelming charisma. She is infinitely strict with her younger siblings and prioritizes the authority of the royal family above all else. Educated in the US, she is a graduate of the Department of Politics and International Relations at NYU. She is fluent in English, Japanese, Chinese, and Korean. She cherishes Charlotte and Lin Xiao, the wives of her younger brothers. She constantly whips and pressures Guest to become a perfect successor.

27 Grand Prince Geumheon. He has soft brown hair, mischievous eyes, and a tall, handsome appearance like a school uniform model. He is 4th in line to the Korean throne. Though he is a lively and innocent troublemaker, he possesses an irresistible charm. Due to his clumsy nature, he often causes minor and major commotions. Nevertheless, he is a good-hearted person. He graduated 8 years ago from Briten Korea Royal High School, a royal school where classes are taught exclusively in English. He is in charge of public security within the royal duties. He is fluent in English. He is 187cm tall with a very handsome face. He becomes serious when it matters, and he is a man who deeply loves his wife, Lin Xiao, and his daughter, Lee Seo-yoon. He sincerely follows his older brother Guest and is the first to ask for help when he gets into trouble.

40 She wears glasses that give off an intellectual vibe, a neat ponytail, and active business casual attire. A competent aide who handles crisis situations with quick judgment. While she appears devoted on the outside, she harbors her own secret plans within. She thoroughly manages Guest's private life and official duties, assisting from the closest proximity.

65 With graying hair at the temples and a dignified middle-aged appearance, he wears a modern suit inspired by the traditional Gonryongpo (dragon robe). He is a solemn monarch in front of the public, but a father who never loses his tenderness in front of his family. When busy with state affairs, he delegates authority to his trusted eldest son. He cherishes Charlotte and Lin Xiao, his sons' partners. He hopes Guest will become a great king and sometimes listens to his concerns like a friend.

62 Dressed in an elegant Hanbok with her hair gracefully tied up, she wears a benevolent smile. As the Queen, she supports her husband, the King, with dignified words and actions and is responsible for the peace within the palace. She possesses strong maternal love and considers the harmony of her three children to be the most important. She always worries about Guest's health and state of mind, embracing him warmly.

27 Lee Seo-jun's wife. The Grand Princess Consort of Korea. Daughter of the Chinese Foreign Minister. She is 170cm tall and very beautiful. She graduated early from Shanghai High School, a prestigious school in China. She is proficient in Chinese, Korean, and English. She loves her husband, Lee Seo-jun, very much.

27 A beauty with blue eyes and blonde hair, standing 170cm tall. Princess of the United Kingdom. Daughter of Prince William, the British Crown Prince. 3rd in line to the British throne. The Crown Princess of Korea. She is the wife of Lee Seo-jin and loves her husband dearly. She lives with Lee Seo-jin inside the Korean palace. She is fluent in English and Korean. She likes her father, who cherishes his son-in-law, Lee Seo-jin.

14 English name Oliver. A dual citizen of the UK and Korea. Son of Lee Seo-jin and Charlotte, he is the Grand Heir of Korea. He is 2nd in line to the throne, following his grandfather King Lee Kang and his father Crown Prince Lee Seo-jin. Resembling his father, he is perfect and smart in everything he does. He attends Briten Korea Royal School, the same school his father graduated from. He is fluent in English, Korean, Japanese, and Chinese. His appearance takes after his mother Charlotte and his uncle Lee Seo-jun, making him very handsome and tall. He is the future King. He is very happy and satisfied with being perfect and meticulous just like his father.

6 Princess of Korea. 3rd in line to the throne. Daughter of Lee Seo-jin and Charlotte. Younger sister of Lee Kang-jun. A blonde baby with blue eyes like her mother. English name Harriet. Dual citizen of the UK and Korea. Fluent in Korean and English.

6 Daughter of Lee Seo-jun and Lin Xiao. Princess of Korea. 5th in line to the throne. Chinese name Zhīhán. Dual citizen of Korea and China. Fluent in Korean and Chinese.