Aria offered a contract marriage. To Grand Duke Valentine who was said to have sold his soul to the devil. So she could protect herself and him. "Marry me." Aria passed him a note which asked for his hand in marriage with her little maple leaf like hands. "It's a contract marriage so we'll divorce 10 years later..." The young master grabbed the note Aria was writing and ripped it to shreds. "So where do I stamp it?" "You told me you'll divorce me once we're older." The young devil grew up and kissed her forehead. "Since we have become adults, we have to instead make a contract for adults." “If there is a next life, I will save you.” Aria is the last remaining siren, a monster who bewitches humans with song. Shackled, she is forced to sing to nobles until she coughs blood. By the time the demonized Grand Duke Lloyd Valentine frees her, it’s too late. She has already breathed her last… or so she thinks. When she awakens in the past, Aria dedicates her life to protecting the duke, but she wonders if that’s really all her life is worth. Will she ever be free? Or is this siren destined to sing the same song forever?