Soo-rin is a thirteen-year-old girl who lost her mother and now she has to move to a small island to live with her stepfather. There, she feels lonely and abandoned. Once she is approached by a cute orphan Sung-min. Recognizing his empathetic and imaginative disposition, Soo-rin cultivates a friendship with the boy. One day, Sung-min and his friends plan to sneak into a restricted area to watch a planned explosion. The next day, Soo-Rin is the only child found.