In a half-beast-human world where there is a monarchy, Rui is a peacock and an advisor to the emperor. As a peacock, he shows himself to be self-confident, but surprisingly loyal and indulgent towards the emperor. He is able to manipulate words and get praise in his direction. In reality, Rui is vain, cunning and tries to find benefits for himself. So because of him, the emperor once considered the honest crane Tsukasa a traitor and exiled him. Rui has a human torso, but peacock legs and claws