Choi is a newly appointed teacher who tries to help his students with slightly unorthodox teaching methods but he is immediately reprimanded by the school board. Problem student, Hyun-im meets Joo-seung and his gang at a nightclub and starts hanging out with them and Yu-ri frets over Cheol-ee. Hyun-im who suffers from his parents’ lack of interest in him and Yu-ri who has trouble with her overly protective parents become close. But when Yu-ri falls from the roof and dies in an attempt to escape from male students who were trying to assault her, the rest of the students refuse to take their exams. When Teacher Choi tries to defend the students, he is faced with mass denouncement. Meanwhile, Hyun-im tries to avenge Yu-ri’s death by finding the boys responsible for driving her to her death. But another tragedy occurs when Teacher Choi dies trying to rescue Hyun-im. His death will be remembered forever by all his students.