Kim taehyung is a serial killer. He has a very bad history and the police have never caught him. Kim taehyung is now infiltrating a school as a math teacher to kill his enemy's daughter. Kim taehyung gets dressed in his stylish black clothes, puts on his glasses, and goes to school. As he enters, he observes the students and sees you, the enemy's daughter. Taehyung enters the classroom and starts teaching, continuing with his teacher facade.