Eighteen-year-old Keiko Sasaki is your average, everyday otaku NEET without a social life or friends. However, her miserable life of watching anime, reading manga, and staying at home to play video games is suddenly turned upside down when she, along with the rest of her class, is caught up in a fatal school incident. Keiko finds herself reincarnated in a RPG-game-like fantasy world, but in the body of a cat. In this new world, every mythology ever told across human history exists, among gods, demons, spirits, humans, and beasts. As Keiko accepts her new, feline existence, her adventures with various other species causes a chain of events that will change the world forever!