Manager of Sales Team 3 at Durumi Electronics. A married woman devoted to housekeeping and childcare, she is also a one-shot, one-kill assassin who executes heinous criminals the law has failed to punish. Nicknamed 'Kingfisher' because she sits high up and charges like a bullet once she spots her prey. At work, she is a cold-headed, charismatic perfectionist, while at home, she lives as an ordinary wife and mother to her husband Kwon Taesung and daughter Kwon Yul. She loves Taesung, whom she met through a special connection during a difficult time in her past, more than her own life and cherishes the ordinary daily life they build together. For Bona, work-life balance means protecting both her convictions as Kingfisher and the happiness of her family. To that end, she strives to keep her 'other side' hidden from her husband. Having returned to the field after three years of childcare leave, will she be able to balance both work and home?

Team Leader of Sales Team 3 at Durumi Electronics - Specialist in Disguising Accidental Deaths. The leader of Sales Team 3, which does completely 'different work' compared to the other four sales teams at Durumi Electronics. He always has a good-natured smile and appears weak and easygoing at first glance, but he hides deep combat prowess behind that facade. He coordinates the team 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 quietly supports and protects Yoo Bona, who returned after three years, acting as a reliable ally.

Section Chief of Sales Team 3 at Durumi Electronics - Specialist in Medical Malpractice. Known as 'Dr. Go.' It's not just a nickname; he is a real doctor—a surgeon, in fact. He gathers medical information needed for 'medical accident' disguise scenarios, executes meetings, and occasionally treats team members injured during the process. He is usually a man of few words but says exactly what is needed at the right time. "(Quietly raising his hand) I believe laundry detergent is a better housewarming gift than toilet paper." "(Raising his hand again) It would be best to wear sneakers for the workshop, wouldn't it?" "(Quietly reaching out his hand) Shall we put our hands together and shout 'Fighting' once?"

Section Chief of Sales Team 3 at Durumi Electronics - Weapons Specialist. Known as the 'Dirty and Smelly Shut-in.' In a corner of the Sales Team 3 office, behind a door disguised as a bookshelf, lies a spacious room where Taemin works and practically lives. Immersed in creating various weapons and equipment, he loses track of time and the rising or setting sun. He eats when hungry, sleeps when tired, and wakes up to work again... While eating and sleeping are essential for human survival, washing is not, so he skips it. Consequently, Taemin's room is filled with dust and a foul stench, and the team members dread opening that door... Into his life comes the 'strange woman' Guest, starting a subtle change in his space-time that seemed like it would never change.

Assistant Manager of Sales Team 3 at Durumi Electronics - Genius Hacker. A computer genius called 'Crazy Fingers.' There is no firewall he cannot breach, no CCTV he cannot control, and no information he cannot find. He mainly supports Yoo Bona's sniping activities from behind, moving as a team. Like many geniuses, he has a somewhat prickly and sensitive personality. While he frequently bickers with Hyunnam, who has a similar temperament, he is quite attentive and kind to Bona. One day, while rushing to help Bona, he becomes entangled in a mysterious relationship with her sister-in-law, Sea.

Assistant Manager of Sales Team 3 at Durumi Electronics - Administrative Office Lead. Known as 'Kind Yesol.' A person who is kind to everyone with a girlish way of speaking and a face full of smiles. She is in charge of 'forging various documents perfectly.' While she mainly handles office work rather than field duty, a 'single blow' can come out of nowhere at any moment. As it turns out, her hobbies include Taekwondo, boxing, and kickboxing... a woman of unexpected depth who hasn't missed a single combat sport.

Former Team Leader of Sales Team 3 at Durumi Electronics - Current Flower Shop Owner. Originally an Oriental medicine scholar, she was an expert in sudden death cases during her active years. Having seen so many horrific things, she wanted to spend the rest of her life looking at only beautiful things, so after retiring, she bought a small building in Bona's neighborhood and opened a flower shop. The first floor is the flower shop, the second floor is her living quarters, and the basement contains a secret training ground for Bona. She carries the pain of being divorced after her husband discovered her true identity. She is a mentor-like figure who gives advice based on her experiences whenever Bona worries about the fear of becoming a mother, the hardships of being a working mom, or issues with her in-laws. She is the only person Bona can truly open up to.