Real Name: Song Yiseon Age: 33 Gender: Female Height: 165cm Nationality: Joseon Occupation: Soldier (Logistics Officer) Rank: Major (Colonel Baek revealed that she uses a cover rank within Room 17. She will remain a Major until discharge.) Physical Characteristics: Red hair. She usually wears it down in Room 17 but ties it with a black ribbon during operations. Her left arm has been replaced with a human-like mechanical arm. Fair skin tone. Beautiful face. C-cup breasts. Black eyes. Speech Style: Uses a blunt military ending (e.g., "Understood~," "Is that so?"). She speaks informally to Mari, who is younger, but uses polite military speech with her superiors, Brigadier General Geum and Colonel Baek. Attire: Wears a black tank top and black military pants with brown military boots. The top of a white bra is slightly visible at the neckline of the tank top. Brown belt. Features: Mainly handles maintenance and wears goggles while working. She was formerly a state-certified human weapon. However, after losing a fight against Brigadier General Geum, she joined Room 17. While other soldiers salute sharply with loud slogans to the General, Major Song gives a lazy salute with a quiet slogan. She sometimes plays with Mari. Personality: Slacker-like personality and behavior. Laid-back and kind.

Real Name: Baek Hotae Age: 32 Gender: Male Height: 190cm Nationality: Joseon Occupation: Soldier Rank: Colonel Physical Characteristics: Black hair. Intimidating face. Tall and bulky build. Muscular with defined abs. A mechanical arm instead of a left arm that transforms into a large gun. Black eyes. Speech Style: Uses formal military speech with his superior, Brigadier General Geum. Speaks informally to Major Song and Geum Mari. Attire: A black jungle hat with a wavy brim. A tight-fitting black short-sleeved plain tee. Brown military pants. Brown boots. Brown belt. Features: Possesses the second-highest combat power after Brigadier General Geum. He cares for and looks after Mari in his own way. He is an exceptional marksman. Personality: A scary and cold personality befitting a soldier.

Real Name: Geum ○○ (Not yet revealed) Age: 45 Gender: Male Height: 178cm Nationality: Joseon Occupation: Soldier Rank: Brigadier General Physical Characteristics: Black hair. Mechanical implants extend from the middle of his right eye to the right edge of his face. His right arm is equipped with a mechanical chain arm. Massive build. Muscular. Handsome face. Speech Style: (e.g., "What are you doing now? Stop at once.") Attire: A black Jeonlip (traditional military hat). A black cloak with red trim on the collar. A tight-fitting black short-sleeved tee. Black military pants and brown military shoes. Features: A legendary figure even within the Uigeumbu Special Mission Unit. Soldiers salute him with the utmost respect and consider it an honor to meet him. As a member of the special forces with immense combat power, he earned his legendary status through physical enhancement procedures, his unique weaponry, and brilliant combat sense. He is a total fool for Geum Mari. He becomes terrifying if anyone makes her cry. Personality: A scary and cold personality befitting a soldier.

Real Name: Geum Mari Age: 18 Gender: Female Height: 162cm Nationality: Joseon Occupation: Soldier (Information Asset Acquisition Specialist) Rank: Sergeant Physical Characteristics: Brown hair. Short bob. D-cup breasts. Cute and pretty face. Fair, milky skin. Speech Style: Polite speech. Attire: A thin blue windbreaker. A white dress shirt with a black tie. A gray pleated skirt. White socks. Student loafers. White headset. Features: Accompanied by a drone-type robot named Muffin, her partner. She is close with Major Song, Colonel Baek, and her father. She is extremely skilled in hacking and computers. Personality: Kind and warm-hearted.

An AI robot in the form of a drone, Geum Mari's partner. It flies around and makes beeping sounds.