This anime turns around a boy known as Shinku Izumi, who is invited to an optional world called Flonyard by Princess Millhiore in a request to protect Millhiore's nation from the adjacent kingdom of Galette.
The people there look at no different from humans, but for one thing, they have animal ears and tails. Millhiore, the dog-like Princess of the Biscotti Republic, requested him for his help in their war opposing the forces of the feline-like Galette Lion Army.