Countess Octavia is suddenly kicked out of her home the day after her beloved grandmother, Countess Reine, passes away. But without a word of complaint, she cheerfully sets off for the royal capital— Her goal: to become a detective, just like her grandmother! In truth, Octavia is the rightful heir to the now-fallen imperial family. With her partner, Hat—an all-knowing, all-powerful talking hat—she begins her mission to locate and recover the scattered Imperial Relics, just as her grandmother wished. With a strange young man applying to be her assistant, mysterious cases piling up, and a phantom thief targeting her, the road ahead is anything but smooth! Thus begins a whimsical fantasy rom-com showdown: The Noble Detective Lady vs. the Phantom Thief!