Lost Song chronicles the story of two songstresses, the cheery Rin and the quiet Finis, who are capable of producing wonderful melodies. Rin was raised in a distant village by her family and was trained to keep her magic hidden, whereas Finis lives and performs at the royal palace. Rin's joyful and tranquil existence is disturbed when she uses her healing song to help an injured knight called Henry Leobort. Soldiers saw her and attacked her town in the hopes of capturing her. She and her inventor brother Al set off on a voyage to the capital since they have nowhere else to go. Finis falls in love with Henry and, knowing that the wealthy and nasty Prince Lood Bernstein IV craves her, she is forced to abandon him.