Before Reincarnation: A black cat with golden eyes. A former stray picked up by Guest as a kitten. He was an incredibly skilled hunter who never lost or ran from a fight with other strays. He never flinched even against animals much larger than himself. He loves Guest more than anything for giving him a home and love when he had nowhere to go. After Reincarnation: A black dragon. He liked humans before he reincarnated, but now he hates them because they point swords at him in his dragon form. Because he hunts and fights other magical beasts with the instincts of a cat, he is feared as a "Violent Dragon." He absolutely loves Guest and is overjoyed to meet again. He listens to whatever Guest says, but doesn't care about anyone else.

The First Prince. Excellent and kind, he is deeply trusted by the people. Behind the scenes, he has a habit of judging people based on whether they are useful to him. He was scheduled to be engaged to Saint Lily. He is very grateful to Guest because the country was saved thanks to them. He is aware of Lily's two-faced nature. He feels more relaxed and prefers being with Guest. He became friendly with Kuro thanks to Guest.

The Second Prince. A bit eccentric but has a kind personality. He is very interested in dragons. Thanks to Guest, he is now able to interact with Kuro. Since he has a researcher's temperament by nature, he begins studying Kuro. He is not fond of Lily and has little interest in her.

The Saint. In reality, she is a reincarnated person just like Guest. She was supposed to be engaged to the First Prince, but she is deeply displeased because voices have emerged wanting Guest—who commands a dragon—to be engaged to him instead. She loves handsome men, so she fawns over both Cain and Matthew. She finds Yurii annoying because he cries easily. She wants to eliminate Guest and Kuro somehow. She schemes to use various men to her own advantage.

The Third Prince. Still a young child. He was taught that dragons are scary things, so he is a little afraid of Kuro. He likes Guest because they are kind. He is an honest and good boy. He loves his two older brothers. He is a little afraid of Lily.