Personality: A cold, rational 'ice queen' type. As a former special forces operative, she possesses strong mental fortitude and decisiveness, never panicking even in crises. Traits: Unrivaled combat ability. Skilled in both hand-to-hand combat and marksmanship. Though she appears blunt, she has a tsundere side that looks after those around her. Appearance: Iconic sharp and sophisticated short-cut hairstyle. Usually wears security guard attire or activewear. Tall with a solid, agile build. A dangerous woman who might betray you at any time. 28 years old.

Extremely generous and magnanimous. His strength lies in his spirit of sacrifice, never hesitating to throw himself into danger for his comrades. A perfect leader: an all-rounder with top-tier stats in intelligence, combat power, and character. 23 years old.

Personality: Appears indifferent and prickly on the outside, but is a classic tsundere with a warm heart and a strong sense of justice. He demonstrates leadership in crises and takes good care of those around him. 25 years old.

Status: A former special forces (707th Special Mission Group) member, currently a mercenary belonging to the security department of a pharmaceutical company called B.I. Medical. Personality: Cold-blooded and mission-oriented, yet shows a relatively more human side compared to his former colleagues Choi Chung-il or Seong Gahyeon. Traits: A 'closed-eyes' character. As expected of special forces, his combat skills in shooting and fighting are exceptional. 27 years old.

Status: The youngest member (Private) of the 1st Squad, 1st Platoon, 666th Unit. Personality: Timid and fearful, but sensible and diligent. A typical 'maknae' character who suffers among his intimidating seniors and is always treated unfairly. Traits: Wears glasses and shows the most realistic reactions among the characters. He suffers the most when the zombie outbreak occurs in the Survival Diary. 21 years old.

Status: Prisoner number 1456. A con artist who lived by deceiving others. Personality Traits: An orphan who learned to deceive people early on to survive. Ability: While physically very weak in a fight, he serves as the brain of the squad with his intelligent strategies and situational analysis skills. 23 years old.

A cheerful mood-maker who displays a brilliant mind in crisis situations. A tsundere Sergeant nearing discharge. 23 years old.

Personality: Fiery. Possesses incredible superhuman strength. 23 years old.

A 3rd-year Mechanical Engineering student at Dongjin University, 23 years old. Although she is very shy, she is a 'soft outside, strong inside' character who steps up most actively to help the protagonist Lee Ju-oh during crises or important moments. 24 years old.

A total deadweight, incompetent, and obese soldier. 21 years old.