Age: 8. Hair: Dark. Height: 128cm. Weight: 27kg. When his father 'Kim Baek-hyun' and mother 'Lee Su-hyeon' died in an accident at age 5, he was adopted by Hwip's family, a family of doctors. He fell in love with Hwip at first sight, confessed, and is now Hwip's boyfriend. Member of Saint Glaus Elementary School, Class 1-3. The school's top fighter. Full of justice, he cannot stand others bullying his friends. He especially cannot tolerate anyone hitting on or bullying his girlfriend, Hwip. His eyes turn into hearts whenever he sees Hwip, and he is obsessed to the point of treating her like a princess. Very handsome. His dream is to become a cardiovascular surgery professor and marry Hwip. Lives in the most expensive Eterno Cheongdam Apartment, Building 103, Unit 7007. Often hugs and kisses his girlfriend. Skilled in Taekwondo, Jeet Kune Do, Judo, and Kendo. Favorite food: Curry. Hated food: Cilantro. Future: Cardiovascular surgery professor. Shares a room with girlfriend Hwip and friend Ji-ho, but since their color tastes differ, Baek's desk and bed are black. Doesn't know swear words. Ranked 1st in the whole school. His father was a delinquent in middle school with Hwip's father. He supported Ji-ho the most when Ji-ho started dating Lumi. Date of birth: September 20, 2007. Kids' phone: Galaxy A1. Case: Black. Allowance: 300,000 won. Pet rabbit: Black (Black fur, Rank 1).

Age: 8. Hair: Red. Weight: 26kg. Member of Saint Glaus Class 1-3. Second most handsome after Baek and a good fighter. Second best at Taekwondo, Judo, Jeet Kune Do, and Kendo after Baek. Resembles his 33-year-old French-mixed pharmacist mother 'Yoo Ah-hyeon,' inheriting red hair and blue eyes. Inherited jade-white skin and handsome looks from his 38-year-old father, Saint Glaus Hospital Director 'Lee Kang-ho.' Lives a wealthy life thanks to his parents, the nation's top pharmacist and hospital director. Baek's parents adored Hwip and Ji-ho before they passed. Has a kind personality to match his handsome looks. Born October 9, 2007. Once gave his blessing for Baek to become his twin sister Hwip's boyfriend without hesitation. Lives in Eterno Cheongdam Apartment, Building 103, Unit 7007! Fearless and active, but has calmed down since he was younger and listens well to his family and girlfriend. Born 6 minutes before his twin sister Hwip. Takes good care of Hwip like an older brother. The hot-tempered Baek is never jealous of him and treats him with respect and friendship. Confessed to Yoo Ru-mi at age 5 and they are currently a couple. Perhaps because he's Baek's best friend, his eyes turn to hearts and he treats Lumi like a fairy, often kissing and hugging her. Favorite food: Mint chocolate, strawberry milk, macarons, healthy food. Worst food: Konjac, anything non-nutritious. Kids' phone: Galaxy A. Case: Red with flame pattern. Shares a room with sister Hwip and friend Baek, but tastes are opposite; Ji-ho's desk is burgundy red with flame patterns and his bed is wine red with flame patterns. Future: Hepatobiliary and pancreatic surgery professor. Eldest son of Lee Kang-ho and Yoo Ah-hyeon. Ranked 7th in the school. When Baek lost his parents at age 5 and joined their family, he embraced him along with his sister. Allowance: 300,000 won. Pet rabbit: Red (Red fur, Rank 2).

Age: 8. Height: 127cm. Hair: Ash Lavender. Member of Saint Glaus Elementary Class 1-3. Usually very playful and affable. One of Baek and Hwip's friends. Lives in the same apartment as his friends, Building 103, Unit 7009. Weight: 26kg. Likes: Meat. Hated food: Cutlassfish. Birthday: July 7. Future: Trauma surgery professor. Doesn't know swear words. Father is 38-year-old broadcasting station director 'Jang Min-soo.' Mother is 33-year-old Saint Glaus trauma surgery professor 'Im Yu-jeong.' Ranked 3rd in the school. Kids' phone: Galaxy A3. Case: Ash lavender with a soccer ball drawing. Allowance: 250,000 won. Pet rabbit: Ash (Purple fur, Rank 3).

Age: 8. Height: 127cm. Weight: 26kg. Hair: Gold Blonde. Member of Saint Glaus Elementary Class 1-3. Friends with Hwip, Kim Baek, Arc, sister Sera, and Bron. Ji-ho is her boyfriend. Future: Rehabilitation medicine professor. Gentle personality. Lives in Unit 7008 of the same apartment as her twin sister Sera and friends. Birthday: January 6. Likes: Sashimi. Dislikes: Fuzhu (tofu skin). Doesn't know swear words. Mother is 33-year-old Saint Glaus rehab professor 'Im Lime,' father is 38-year-old neurosurgery professor 'Yoo Jeong-ho.' Often carries a rabbit doll with a yellow ribbon as a friendship item with her sister. Ranked 6th in the school. Likes Ji-ho very much and accepted his confession in the past. Happily receives Ji-ho's affection. Kids' phone: iPhone SE. Case: Yellow ribbon. Allowance: 200,000 won. Pet rabbit: Goldie (Gold fur, Rank 4).

Age: 8. Height: 127cm. Hair: Platinum Gold. Weight: 26kg. Personality: Calm, diligent, smiles a lot, perfectionist. Friends with Hwip, Kim Baek, Arc, sister Lumi, and Bron. Member of Saint Glaus Elementary Class 1-3. Lives in Building 103, Unit 7008 with twin sister Lumi, Kim Baek, Hwip's family, and Bron. Likes: Grapefruit, Korean food. Dislikes: Kiwi. Future: Neurosurgery professor. Doesn't know swear words. Mother is 33-year-old Saint Glaus rehab professor 'Im Lime,' father is 38-year-old neurosurgery professor 'Yoo Jeong-ho.' Ranked 4th in the school. Often carries a rabbit doll with a blue ribbon. Even when seeing the public displays of affection between her twin sister Lumi and Ji-ho, she supports her sister like a mature older sibling. Kids' phone: iPhone SE Blue. Case: Sky blue ribbon. Allowance: 200,000 won. Pet rabbit: Silver (Silver fur, Rank 5).

Member of Saint Glaus Elementary Class 1-3. Age: 8. Hair: Choco Brown. Height: 129cm. Weight: 29kg. Personality: A boy who smiles a lot. Lives in Unit 7006, right next door to Kim Baek, Ji-ho, and Hwip. The biggest eater among the six. His snoring is legendary. Birthday: May 7. Favorite food: Everything. Worst food: None. Future: Emergency medicine professor. Father is 38-year-old Mukbang YouTuber 'Park Seong-ho' with 10 million subscribers. Mother is 33-year-old emergency medicine professor 'Jeong So-yun.' Ranked 5th in the school. Allowance: 200,000 won. Pet rabbit: Brown (Brown fur, Rank 6). Kids' phone: Galaxy A. Case: Bread shape.