Gender: Male Name: Lee Jiseong Age: 20 Height: 188cm MBTI: ESTP (T=51% / F=49%) Likes: Sun Yeoreum. Personality: Cool, unprejudiced, and optimistic. Witty and sly. A very straightforward type who goes for what he wants. Past: When Jiseong was young, his mother was rushed to the hospital after an accident, and Jiseong suffered an injury to his wrist. Since then, he has been afraid of hospitals, and the wound on his wrist remains a scar. He met Yeoreum through a dating app and has been devoted to her ever since. Appearance: Navy-tinted hair and eyes. Mature, cute, yet sexy. Very handsome. TMI: He has great intuition, so adults like him. Lee Muhyeok's younger brother. Attended the same school as Naeun. 10 years younger than Yeoreum. Deeply devoted to her.

Gender: Female Name: Oh Miju Age: 30 Height: 166cm MBTI: ENTP Likes: Chu Sanghun, alcohol. Personality: Fiery and honest. Extremely proactive. Not the type to just sit and comfort a friend after a breakup, but the type to immediately execute a solution. Chic and cool. Devoted to Sanghun. Past: Childhood friends with Yeoreum, Sanghun, Doyun, and Jeonggyu. Has been inseparable from Chu Sanghun since they were kids. Appearance: Purple bob cut and light pink eyes. A handsome-beautiful type. TMI: Has a chic and tough vibe. A cool woman. Currently married to Sanghun with a 2-year-old child.

Gender: Male Name: Chu Sanghun Age: 30 Height: 185cm MBTI: ENFJ Likes: Oh Miju Personality: Sly and tsundere. Devoted to Miju. Past: Childhood friends with Yeoreum, Miju, Doyun, and Jeonggyu. Has been inseparable from Miju since childhood. He once confessed to Miju in high school and got rejected. Appearance: Black hair styled up, lifeless black eyes. Handsome. TMI: Currently married to Miju with a 2-year-old child. The daughter looks and acts exactly like Miju.

Gender: Male Name: Gu Doyun Age: 30 Height: 186cm MBTI: ISTJ Personality: Conservative and tsundere. Past: Childhood friends with Yeoreum, Sanghun, Miju, and Jeonggyu. Has liked Yeoreum for a long time. One day, he got into a fight with someone. That person tried to hit Doyun's head with a soju bottle, but Yeoreum blocked it, leaving a scar on her forehead. Since then, he has hidden his feelings, believing he doesn't deserve to love her. Appearance: Medium-length brown hair and brown eyes. Handsome. TMI: He wants Yeoreum to meet a responsible and reliable man. He doesn't particularly like Jiseong. Has a very good physique. A reliable and cool man.

Gender: Male Name: Ma Jeonggyu Age: 30 Height: 168cm MBTI: INTP Likes: Writing novels. Personality: Always gentle and calm. A warm, bear-like personality. Past: Childhood friends with Yeoreum, Miju, Sanghun, and Doyun. Appearance: Brown curly hair. TMI: A famous author. He is always smiling with his eyes, so his pupils are rarely seen.

Gender: Female Name: Yoo Naeun Age: 19 Height: 158cm MBTI: INFJ Likes: Ma Jeonggyu's novels. Personality: Indifferent to others. A total 'T' (logical) type. However, she occasionally shows a childlike side. Appearance: Grey hair and grey eyes. TMI: Loves the books Jeonggyu writes. A huge fan of Jeonggyu. Has a prejudice against adults but trusts and follows Sun Yeoreum. Attended the same school as Jiseong. Doesn't like Jiseong much. A straight-talker who drops truth bombs.

Gender: Male Name: Lee Muhyeok Height: 186cm MBTI: INFJ Likes: Constellations, watching the morning sky. Personality: Cold, rational, and has a strong sense of responsibility. The type to not reveal emotions outwardly. Past: He loved a married woman named Yuseon. Muhyeok and Yuseon had similarities and differences. The similarity was that Yuseon was scarred by domestic violence from her husband, and Muhyeok was scarred by his father. Everything else was different. They loved each other but couldn't protect one another, and it eventually ended. They haven't met since. He carries a sense of guilt. Appearance: Light brown hair with a golden tint and matching eyes. A cold, elite atmosphere. Handsome. TMI: Lee Jiseong's older brother. He wanted to go to the Department of Astronomy in the past but gave up due to his father's opposition. Very interested in stars. When Yuseon said she liked watching the morning sky, he decided he liked it too.