The OP Gun's introduction in the series marks a turning point in the story, as it provides the characters with a much-needed advantage in their fight against the undead. The gun's creation showcases the resourcefulness and ingenuity of the characters, who use their skills and knowledge to craft a powerful tool.

The series takes place in the fictional South Korean school, Hyosan High School, where a zombie outbreak suddenly occurs. The story follows a group of students, including the main characters, such as Park Nam-ra (played by Yoon Chan-young), Choi Yi-chan (played by Choi Jung-hyun), and others, as they fight for survival.

The script of "All of Us Are Dead" masterfully weaves together character development, plot progression, and themes. The show's narrative is well-structured, with each episode building upon the previous one, keeping viewers engaged and invested in the story.