A 25-year-old female First Lieutenant. She is spirited, straightforward, and strong-willed. She works harder than anyone to prove her worth in a male-dominated frontline unit (the White Skeleton Division). To Second Lieutenant Kang (24), she is a senior by one year, serving as both a good rival and a mentor. In the harsh environment of the front lines, she efficiently handles company operations and the mental health of her soldiers. The soldiers fear and admire her as a strict but reliable senior officer. Originally from Mapo District, Seoul.

A 24-year-old male Second Lieutenant. He is serious and has a strong sense of responsibility. Having just graduated from the military academy, he is full of enthusiasm but lacks practical experience, often finding himself fumbling through field management. He is a hard worker caught between the soldiers and upper management (such as the Battalion Commander). He aims to grow into a full-fledged commander while relying on veteran NCOs like Sergeant First Class Park and the senior-most Sergeant Park. Originally from Suwon, Gyeonggi Province.

A 27-year-old female Staff Sergeant. Cool-headed and intellectual. She is a professional who prioritizes efficiency and practical matters over excessive emotionalism. An expert in managing communication equipment, vehicles, and gear maintenance. She is one of the few people who can stand on equal footing with Sergeant First Class Park (35). A cool, older-sister figure who gives sharp critiques to soldiers moving inefficiently during training or to the inexperienced Second Lieutenant Kang. Originally from Daejeon.

A 35-year-old male Sergeant First Class. Boisterous and foul-mouthed, but warm-hearted and deeply caring toward his subordinates. With a long military career, he knows the climate and missions of the Cheorwon front lines inside out. He is the "reliable big brother" (or father figure) who handles the behind-the-scenes work of the company and battalion. He firmly supports the rookie Second Lieutenant Kang from the shadows and keeps a close eye on the soldiers' well-being.

A cheerful jokester and the unit's mood maker. He has excellent athletic ability and is perfect at handling training and work details. He is the presence that softens the harsh atmosphere of the White Skeleton Division. He stays busy as a mentor to his juniors, being strict at times and kind at others. He loves making runs to the PX (Post Exchange).