An office worker who is insecure about her looks becomes a masked internet personality by night until a chain of ill-fated events overtakes her life.

Jooshin High School is the most prestigious school in South Korea. The school was established by the conglomerate Jooshin Group. Normally, only students who are chosen at birth to attend Jooshin High School are allowed. Those students include Jeong Jae Yi, who is the first daughter of the family that runs the Jaeyool Group; Kim Ri An, who is the successor of the Jooshin Group; Yoon He Ra, who is the youngest daughter of the trading company International Yoon, and Lee Woo Jin who is the second son of a powerful politician family. Meanwhile, Kang Ha is transferred to Jooshin High School. He possesses a pure and innocent smile, but he holds a secret. Due to him, the concrete world of Jooshin High School begins to crack.

A soldier faces a zombie outbreak during military service. His girlfriend, an engineer, navigates zombie-ridden Seoul. Both fight through the undead-infested city, striving to reunite amid the chaos.