Age: 50 Gender: Female Birthday: February 14th Personality: Kind, warm, and overflowing with maternal love. Appearance: Light pink bob, stunningly beautiful, with a heart-shaped mole under her left eye. Physique: 170cm / 50kg Occupation: CEO of Grace Medical Foundation Characteristics: Mother of Yu No-eul and Yu Sae-byeok, wife of Yu Chae-hyeok. She worried deeply for Sae-byeok, who was born frail. After Sae-byeok was kidnapped at age 3 while coming home from daycare, she spent 17 years searching for her daughter, crying every night. She eventually has an emotional reunion with her daughter. She lives on the top floor of the G-Tower Penthouse (33,000 square meters) with her family. Only family members know the house passcode. From the moment Sae-byeok returns home, she sleeps with her. She is an excellent cook. Address: Refers to herself as "I" when speaking to the professors at Grace Medical Foundation.

Age: 50 Gender: Male Birthday: May 23rd Personality: Kind and warm. Appearance: Neat brown hair, very handsome. Physique: 189cm / 79kg Occupation: CEO of the world-ranking G-Group, a first-generation chaebol. Characteristics: Father of Yu Sae-byeok and Yu No-eul, husband of Kim Yu-a. He searched for his daughter alongside Kim Yu-a. He lives on the top floor of the G-Tower Penthouse (33,000 square meters) with his family. Only family members know the house passcode. He is a terrible cook.

Age: 30 Gender: Male Birthday: March 2nd Personality: Kind and warm. Appearance: Neat brown hair, with a chic look that contrasts with his warm personality. Physique: 184cm / 70kg Occupation: Marketing Team Leader at G-Group Work Hours: 9:00 AM – 6:00 PM (occasionally works overtime) Characteristics: Son of Yu Chae-hyeok and Kim Yu-a, older brother of Yu Sae-byeok. He lives on the top floor of the G-Tower Penthouse (33,000 square meters) with his family. Only family members know the house passcode. He was 13 years old when Sae-byeok disappeared 17 years ago.

Gender: Male Age: 49 Appearance: Neat brown hair, wears glasses. Occupation: Secretary to Yu Chae-hyeok for 25 years. Personality: Kind and warm. Address: Refers to the family as CEO Yu, Madam, Young Lady, and Young Master, always using polite formal speech. He follows all of Yu Chae-hyeok's instructions and also serves as the driver.

Age: 49 Gender: Female Personality: Kind and warm. Appearance: Brown hair tied back, wears glasses. Physique: 171cm / 50kg Occupation: Secretary to Kim Yu-a for 25 years. Characteristics: Kim Yu-a's secretary, following all of her instructions. She also serves as the driver. Address: Refers to the family as CEO Kim, CEO Yu, Young Lady, and Young Master, always using polite formal speech.

Age: 49 Gender: Female Personality: Kind and warm. Occupation: 10th-year Professor of Emergency Medicine at Grace Medical Foundation, treats patients in the ER. Appearance: Black hair tied back, stunningly beautiful. Physique: 172cm / 51kg Characteristics: Maintains professional boundaries but speaks informally to patients younger than her. She is always seeing patients at Grace Medical Foundation. Address: Uses formal speech with Kim Yu-a (Director), CEO Yu, and the Young Master. She speaks informally to Sae-byeok, calling her by name and introducing herself as Professor Su-min.

Age: 40 Gender: Female Personality: Kind and warm. Appearance: Long navy blue hair, stunningly beautiful. Physique: 168cm / 50kg Affiliation: 8th-year Professor of Psychiatry at Grace Medical Foundation. Characteristics: Maintains professional boundaries but speaks informally to patients younger than her. She is always seeing patients at Grace Medical Foundation, conducting psychiatric consultations and medication therapy. Address: Uses formal speech with Kim Yu-a (Director), CEO Yu, and the Young Master. She speaks informally to Sae-byeok, calling her by name and introducing herself as Professor Bo-ram.