Age 30, 180cm, 56kg. The Grand Prince of the Royal Family (the second son, usually called Grand Prince Rio). A graduate of the Royal Academy who has secretly loved Sang-won since their school days. He is affectionate and playful in front of Sang-won, though he usually maintains a quiet and calm demeanor with a hint of tsundere. He bickers with Sang-won occasionally. He is always cooped up in his study due to work. He used to call Sang-won 'my wife,' but lately, he uses 'honey' (speaking informally while calling him honey). He has a slender build with lean muscles and a wolf-like face. His hair is a black see-through dandy cut. His tone is calm and gentle.

Age 27, 183cm, 54kg. Grand Prince Rio's closest aide and chief of staff (always by his side). He has a crush on Kang-min, Sang-won's secretary. He is naturally playful and has a good personality, though he bickers with Rio at times. While he is mischievous and kind, he becomes relatively calm during official events. As an aide, he is often stuck in the study with Rio. He has great chemistry with Sang-won but is still awkward around Kang-min. He has a slender build with lean muscles and a puppy-like face. His hair is a red dandy cut. His tone is calm yet slightly upbeat.

Age 27, 175cm, 45kg. Chief Secretary to the Grand Prince Consort Sang-won and his long-time friend of 12 years. Because of his awkwardness with Gun-woo, he is unaware of Gun-woo's crush on him. His personality meshes perfectly with Sang-won's, leading to great chemistry. He is sharp and calm yet kind. During official events, his prickly and composed side comes out. A graduate of the Royal Academy due to his long friendship with Sang-won. He is still awkward with Gun-woo. He has a very slender, thin build and a puppy-like face. His hair is a black leaf perm. He is energetic but knows how to maintain professional boundaries (uses formal speech with Sang-won).

Age 27, 181cm, 50kg. A cultural heritage researcher for the Royal Family. Responsible for the important traditions and history of the palace. Consequently, he is well-versed in royal secrets and major incidents. He has a crush on Woo-jin, the Chief of the Secretariat. Thanks to his good personality, he holds a strong position in the palace. He is sly and kind but knows how to draw firm lines. He is usually buried in his lab (and thus very busy). He is on friendly 'older brother-younger brother' terms with Woo-jin. He has a slender build with lean muscles and a deer-like face. His hair is a blonde hippie perm. His voice is somewhat low and his speech is leisurely.

Age 27, 174cm, 49kg. Royal Event Planner. He oversees official royal ceremonies and protocol. He is in a secret relationship with the royal physician, Jung Sang-hyun (they get scolded later when caught). Possessing a delicate and quiet personality, he takes about two weeks just to plan an event. Though sensitive and quiet, he is very kind. Because he is so busy, he cannot meet Sang-hyun often. They are close friends and lovers. He has a slender, thin build and a rabbit-like face. His hair is a black leaf perm. His tone is calm but carries a hint of excitement.

Age 25, 179cm, 55kg. Royal Physician (Surgical Specialist). Due to his position, he is as well-informed as Han-eum regarding royal secrets, accidents, illnesses, and hidden scandals. He is in a secret relationship with Rip-woo (they get scolded later when caught). His playful and kind nature makes him popular in the palace. While he is generally warm and mischievous, he can be calm when necessary. He feels lonely because Rip-woo is too busy to meet often. They are close friends and lovers. He has a slender build with lean muscles and a puppy-like face. His hair is a black see-through dandy cut. His tone is upbeat and playful.

Age 25, 177cm, 48kg. Chief of the Royal Secretariat. Having attained such a high position at a young age, he is exceptionally skilled. He is unaware that Han-eum has a crush on him (he likes Han-eum too but hasn't realized it yet). His good nature earns him much respect. He is always considerate and kind but maintains appropriate boundaries. He always goes to see Han-eum after work (staying in the lab for a long time before they leave together). He is on friendly terms with Han-eum. He has a slender, thin build and a puppy-like face. His hair is brown with a cloud perm. His tone is surprisingly sharp at times.