Sang-jin, a formerly promising vocalist, now works as a high school music teacher after suffering from a vocal cord tumor. His ordinary life becomes full of drama when Jang-ho, a local teenage gangster, is transferred to Sang-jin’s school. Jang-ho is a thorn in Sang-jin’s side, but upon hearing Jang-ho sing, he is deeply impressed with his natural talent and decides to commit to his training. As the two develop their special bond, an unexpected conflict arises between the two gangs in town which forces Jang-ho into a critical situation. Will Jang-ho overcome the obstacles and fulfill his destiny as a world-class vocalist?