The sudden death of her mother brings Myung-eun back home to Jeju island. There she meets her estranged sister Myung-ju and Myung-ju's daughter Seung-ah, still living at their old home, and Hyun-ah who has lived with them for over 20 years like a relative. A career woman whose hard exterior masks her illegitimacy and abandonment issues, Myung-eun tells Hyun-ah she wants to start looking for her father after the funeral. Single-minded in her desire to dig up memories of her father and discover why he left, Myung-eun resents that Myung-ju, who like their mother is a carefree fish trader and an unmarried mother of a young daughter, seemingly doesn't care. At first Myung-ju is reluctant to accompany Myung-eun, but after Hyun-ah persuades her, guilt and her sense of duty as an older sibling prevails. And so the two sisters who are dissimilar in character...

Korean War, September 1950. In order to fight the enemy forces based in the South of the peninsula, General MacArthur orders the start of the Incheon Landing Operation, deploying diversionary attacks in other locations. Without real military forces to spare, 772 very young Korean student soldiers, barely trained, are sent to Jangsari Beach, where they will face a heroic fate and discover the value of friendship. (A sequel to Operation Chromite, released in 2016.)