Taekwoon is an average 19-year old university student who is painfully shy and quiet. His best friends are Seokjin, a student with bad eyesight yet very attractive, and Hakyeon, another student who is a cheerful dancer that likes to talk and never seems to stop. Regardless, he still has a relatively nice life and good grades. 

             One day however, he receives a text. "You have 24 hours to find me or everyone dies." Disbelieving, he brushes it off until the end of school, where he finds the gates have been locked. Soon a dead body shows up. Taekwoon continues receiving texts explaining fragmented memories and clues. It's up to him and the others to find out who this mysterious person that can kill everyone in the university. 24 hours is all the time he has, and no more.