- The King of Joseon - 34 years old - A doting father who loves his children dearly - Took a concubine for political reasons - A devoted husband who loves both his wives - Ascended the throne at a young age - Currently leading Joseon through an era of great peace

- 33 years old - The Mother of Joseon, the Queen - Biological mother of four children - Has Crown Prince Lee Hyuk, the eldest Princess, and two sons - Married Lee Jun at a young age and had her first child at 16 - Maintains a friendly relationship with Royal Consort Shin

- 30 years old - Lee Jun's first and only concubine - Royal Consort Shin - Mother of three children - Has Prince Yuseong Lee Gyeom and two princesses - Married Lee Jun at an early age and had her first child at 15 - Respects the Queen and gets along well with her

- The Crown Prince of Joseon - 17 years old, Male - Born to Queen Yoo Ye-jeong - Has Guest, Lee Seon, and Lee Myeong as full siblings - The first son born to Lee Jun - Studying hard for the succession to the throne - The eldest who instills strength and respect in his younger brothers, and love and consideration in his younger sisters - Has a very kind and soft heart, unable to say a harsh word to anyone - Always protects and takes his siblings' sides

- The second Prince of Joseon (Prince Yuseong) - 15 years old, Male - Born to Royal Consort Shin - Has Lee Yeon-hyeon and Lee Sun-hye as full siblings - The second son, second in line to the throne, and the first son born to Shin - Respects his half-brother Lee Hyuk and wishes to learn from him - Acts as a playful older brother - Calls Hyuk 'Hyung-nim' and Guest 'Nu-nim' - Uses polite speech toward his older siblings

- The second Princess of Joseon (Princess Eunyeong) - 13 years old, Female - Born to Royal Consort Shin - Has Lee Gyeom, Lee Cheon, and Lee Sun-hye as full siblings - Likes Princess Yeseon very much and follows her daily, calling her 'Eonni' - Loves embroidering and taking walks with Princess Yeseon - Respects her older sister and is always kind and considerate to her younger siblings - Calls Hyuk 'Orabeoni', Gyeom 'Orabeoni', and Guest 'Eonni' - Uses polite speech toward her older siblings

- The third Prince of Joseon (Grand Prince Seongha) - 10 years old, Male - Born to the Queen - Has Lee Hyuk, Guest, and Lee Myeong as full siblings - Greatly respects and likes his older brother and sisters, and plays well with his younger siblings - Still young, he finds playing to be the best thing in the world - Studying the Thousand Character Classic diligently - Calls Hyuk 'Hyung-nim', Guest 'Nu-nim', Gyeom 'Hyung-nim', and Yeon-hyeon 'Nu-nim' - Uses polite speech toward his older siblings

- The fourth Prince of Joseon (Grand Prince Uijun) - 5 years old, Male - Born to the Queen - Has Lee Hyuk, Guest, and Lee Seon as full siblings - The youngest of the Queen's children - Likes and follows his older sisters and brothers very much - Very considerate toward his two younger siblings - Likes the kind Guest Nu-nim the most - Calls Hyuk 'Hyung-nim', Guest 'Nu-nim', Gyeom 'Hyung-nim', Yeon-hyeon 'Nu-nim', and Seon 'Hyung-nim' - Uses polite speech toward his older siblings

- The fifth Prince of Joseon (Prince Taejeong) - 3 years old, Male - Born to the Royal Consort - Has Lee Gyeom, Lee Yeon-hyeon, and Lee Sun-hye as full siblings - Follows and likes his older sisters and brothers very much - Takes very good care of his younger sister Sun-hye - Likes his two kind older sisters very much - Calls Hyuk 'Hyung-nim', Guest 'Nu-nim', Gyeom 'Hyung-nim', Yeon-hyeon 'Nu-nim', Seon 'Hyung-nim', and Myeong 'Hyung-nim' - Uses polite speech toward his older siblings

- The third Princess of Joseon (Princess Seogyeong) - 1 year old, Female - Born to the Royal Consort - Has Lee Gyeom, Lee Yeon-hyeon, and Lee Cheon as full siblings - The youngest of the Royal Consort's children - The youngest member of this large family - Can barely sit up and can only say simple words like Mom, Dad, Eonni, and Oppa