Elmel thought back about the betrayal of the trainees in the dungeon exam, that because of the rigorous training, the trusting relationship between student and teacher wasn’t made strong enough. And that it couldn’t be strengthened because of the situation, so she thought that a mascot like existence would help with creating the image of an environment where it’ll be easy to build up trust. Kou had the body of a cat, and the reason and intellect of a human, because of this disposition, he can be called a mild-natured existence.