Sold off as a maid at a young age, Laveri Atelier grew up without education or privilege. But her innate talent for writing earned her renown among commoners as Madame Rosa, the most sought-after ghostwriter of love letters in town. One day, she receives an unusual commission from an anonymous noble, to pen a series of ardent letters addressed to their younger brother, Cedric. Eager to earn enough money to escape her life of servitude, Laveri begins crafting letters filled with flirtation and desire. But before long, she receives a reply, with her real name written clearly at the bottom.