During the Korean War, a platoon leader of the South Korean army named Sang-ryul is exhausted by never-ending combats and nightmares from the death of his family. He gets newly assigned as a choir leader at an orphanage operated by the army and meets Dong-gu and Suni, sibling war-orphans who lost their father due to Suni’s mistake for singing North Korean national anthem in front of South Korean soldiers. Due to the trauma of Suni’s father’s death, Suni stops singing since then. Sang-ryul learns that orphans have been making a living off of smuggling oil from abandoned war machines and by selling misfired explosives back to the army. With the orphanage caretaker Joo-mi, Sang-ryul begins to teach songs to children and orphan-choir’s show goes on a tour. Due to the popularity of the orphan-choir, captain of the platoon orders Sang-ryul to take the choir to the front line of the war. Sang-ryul refuses to take the order and decides to disband the choir because he is afraid that the children will be in danger; however, orphans step up and agree to stick together like a family. During the last performance, sudden gun-shoot occurs and Dong-gu dies while trying to save Suni. The war finally ends and Sang-ryul prepares the last stage with the orphan-choir. In memory of Dong-gu, Suni dedicates Dong-gu’s favorite song in front of the audience.