Yuna is a normal high school girl at Jeonseo High School. She lives a normal life, with a few close friends and acquaintances. She never had a complaint about her life because it's easy-going and peaceful. Suddenly, when a laboratory near her school exploded and encountered a security breach, creatures were on the loose. They start to mimic human forms but it's not always perfect. This has caused students of the Jeonseo High School to remain in the school while the military fight against the skinwalkers roaming Korea. Will Yuna and her friends make it out alive from this nightmare? Get ready for a non-serious adventure of these 5 people as they navigate through survival, romance, and violence.