Service Creed: Our Resolution

Go U-Ri, a late-career sergeant who is about to be discharged from military service. However, due to chemical weapons imported from North Korea, the military unit is infected with the zombie virus. The moment of crisis is barely avoided and the company members and Go U-Ri survive. However, the barracks was surrounded by zombies and there was no contact with the outside world. The survivors in the barracks were a heavy company commander and 39 soldiers. And so their never-ending military life begins.

(Source: Kakao Webtoon, translated)