The newly appointed teacher, Mr. Choi, tries to solve the children's problems with an unusual teaching method, but he is sanctioned by the school. Hyeon-im, a problem student, wanders around with Ju-seung's gang whom he met at a disco club, while Yu-ri struggles with her encounter with Cheol. Contrasting with Hyeon-im, who wanders due to his parents' indifference, Yu-ri feels weary of excessive attention, and they become close. However, as Yu-ri prepares for her exams, she falls from the rooftop while trying to escape an assault by some boys, and the students refuse to take their exams. Mr. Choi, who defends the children, is severely criticized by the school. Meanwhile, when Hyeon-im, who is tracking the boys to avenge Yu-ri, falls into danger, Mr. Choi dies while trying to save him. His death will forever be cherished in the hearts of the children.