Age: 36 Gender: Male Occupation: Social Affairs Reporter at Not Today News Family: Wife Yu Bona, Daughter Kwon Yul A devoted husband who believes meeting, loving, and starting a family with Yu Bona is the best thing he has ever done. While he is a doting father, he is also a passionate reporter who chases scoops by diving headfirst into injustice. Having once specialized in covering 'Kingfisher,' he neither blindly follows the vigilante nor labels them a simple criminal. Recognized by readers for his balanced perspective and deep reporting, he once suddenly dropped all coverage of Kingfisher, sparking curiosity among his colleagues. On the day his wife returns to work after three years, Kingfisher—whom he thought had retired—reappears, and he begins to be shaken by memories buried deep in his heart. Later, he tracks Kingfisher again for a specific reason, facing a great conflict between his mission as a reporter and his responsibility as the head of a household.

Age: 36 Gender: Male Occupation: Inspector, Violent Crimes Team 1, Southern Police Station Taeseong's best friend and an ace detective who always ranks at the top for arrest rates. Having experienced a tragic event during his school years, he understands the pain of crime victims better than anyone, but he is a man who chose the path of legitimate legal judgment over private revenge. He believes that murder is not justified just because Kingfisher targets heinous criminals, and that Kingfisher is merely another criminal. A determined pursuer who cannot understand the public's adoration and enthusiasm for Kingfisher. He stakes his life on the investigation, believing that catching Kingfisher is his 'job' as a police officer and the path to true justice.

Age: 58 Gender: Male Occupation: Team Leader, Sales Team 3, Durumi Electronics / Specialist in disguising deaths as accidents The leader of Sales Team 3, which does completely 'different work' compared to the other three sales teams at Durumi Electronics. He always has a kind smile and appears weak and easygoing, but he hides deep combat prowess behind that facade. He leads his team members to craft meticulous scenarios and conducts client meetings relentlessly, yet he is a man of innate humanity who gazes at the sky with a heavy heart afterward. He silently supports and protects Yu Bona, who has returned after three years, acting as a reliable ally.

Age: 4 Gender: Female Family: Father Kwon Taeseong, Mother Yu Bona Bona and Taeseong's daughter, the apple of their eye. The darling of the Kwon family. Although she is only three years old in international age, she speaks early for her age and has a lively personality, earning love from everyone. However, being at an age where she requires a lot of attention and having never been away from her mother for long, she becomes the biggest variable in Bona's life as a working mom after her return to work.

Go Yeonggap, Gi Yeongdo, Bong Taemin, Oh Hyeonnam, and Yang Yesol appear to be ordinary office workers, but they are actually expert killers. Go Yeonggap: Specialist in medical accidents, Doctor / Male Gi Yeongdo: Genius hacker / Male Bong Taemin: Weapons specialist / Male Oh Hyeonnam: Poisoning specialist / Female Yang Yesol: Administrative and office support / Female

Age: 27 Gender: Male Occupation: Detective, Violent Crimes Team 2, Seoul Southern Police Station A simple and pure-hearted police officer. He serves as a loyal and passionate partner to Lee Dongjin in the process of tracking Kingfisher.

Age: 26 Gender: Female Occupation: Rookie Reporter at Not Today / Taeseong's junior Initially confused by Taeseong, her first senior at her first job, she soon recognizes his true worth and follows him diligently, learning as they track various cases together.