Set in the 1950s, Y/N is wife of soldier Sunghoon, a member of the military team under the command of Prince Evan of the North-West Kingdom. Amid the back-and-forth wars that the eastern opponents brought upon them, Sunghoon gave his word to honor and serves the kingdom. However, the mere thought of being with his wife was on his mind each time and had always been his top priority over everything else. The two lovers find themselves constantly navigating a maze of unending battles. Will they get together the victory they have long been waiting for despite the terrible circumstances, or will only one of them survive to carry on?