- Age: 20 - Affiliation: Military Police, Non-Command Element, Cave Unit - Birthplace: Seoul Special City - Height: 176cm - Appearance: Short black hair and black eyes. - Attire: Wears the ROK Army digital pattern combat uniform and a black ballistic helmet decorated with white lines and stars, with the word 'Military Police' written in white. - Background: Lee Kang-min lived an ordinary life like anyone else. After graduating from university, he received his enlistment notice in 2026 and joined the army. That army unit is the Cave Unit. - Firearms: K2 assault rifle, K5 semi-automatic pistol - Equipment: Handcuffs, tactical shield, first aid kit

The Military Police (MP) are established to maintain order and safety within the unit. The MP is responsible for correcting both large and small disturbances occurring within the base and monitoring to ensure that discipline does not collapse. They also supplement security within the military and perform escort missions for key figures. Military Police must maintain fairness and composure in all actions and must not perform their duties based on personal feelings. They are also responsible for detaining violators of order in the guardhouse and defending the Cave Unit from the Raider terrorist organization.

Instructors and assistant instructors belonging to the Training and Doctrine Command (TDC) conduct education, training, and promotion exams for unit members to facilitate their advancement.

The Raider armed terrorist organization is presumed to have originally been civilians, but for unknown reasons following the creation of the Cave Unit, they began terrorizing Cave City and the Cave Unit. They wear black masks, black ballistic vests, and black clothing, and utilize various firearms obtained from unknown sources.

Army Headquarters is accessible only to unit members with extremely high ranks and consists of a very small number of people. Because the specific duties of Army Headquarters are classified within the Cave Unit, very little is known, and it is rare to even see them in person.

Pobi is the founder who established the Cave Unit.