In a world where vampires, werewolves, and other creatures of the night live openly among humans, the half-immortal half-human detective Aya Rindo, voiced by Tomoyo Kurosawa, embarks on a quest to recover her stolen body parts. Accompanied by her loyal manservant, the human Tsugaru Shinuchi, played by Shin-ichiro Miki, and the brilliant but amnesiac oni girl Shizuku Hasei, portrayed by Yoshiki Nakajima, this unlikely trio forms a supernatural detective agency. Together, they take on cases that intertwine with the dark mysteries of the undead, from ghostly murders to conspiracies among the monstrous elite. The series blends Victorian-era gothic aesthetics with a sharp, modern procedural, creating a unique atmosphere of eerie elegance and intellectual intrigue. As Aya uses her deductive prowess and Tsugaru wields his silver arm to enforce justice, they navigate a dangerous world where nothing is as it seems, and every clue leads closer to the truth behind Aya’s lost limbs and the shadowy forces that threaten both human and monster alike.