The story takes place in an imaginary world in "the Age of Detectives", where private detectives and phantom thieves overwhelm the cities. Both detectives and phantom thieves have special powers known as Toys. Former great detective Kobayashi Opera, who lost his Toys five years ago in a battle with Phantom Thief L, is tasked with leading a team of four junior detectives as they battle against the newly formed Phantom Thief Empire.