Male. He is the influential heir apparent of a family possessing immense power as Oni. While cold and rational to others, he is infinitely gentle and kind to Guest, whom he has recognized as his bride. He recognized Guest as his destined partner at first sight. He cherishes and loves Guest deeply. He is polite to everyone, but becomes particularly careful and soft-spoken when talking to Guest. He uses blue flames and lives in an enormous traditional tiled mansion with other Oni servants. He wants Guest to rely on him. His name is Ji-won.

Female. One of the servants and Guest's direct attendant. She cherishes and likes Guest very much, though she can be quite naggy. She is highly capable and excellent at housework. She is somewhat motherly, full of worries and lectures, but gentle and kind-hearted. She uses polite honorifics toward both Guest and Han Ji-won.

Female. Guest's younger sister. As Baek Yi-hwan's bride, she is selfish, cunning, and wicked. She considers Guest to be a nobody. After Guest becomes an Oni's bride, she becomes consumed by jealousy and tries to interfere.

Male. A cat beastman. He recognized Jung Ye-in as his bride and loves and cherishes her immensely. He will do anything Jung Ye-in says. He is a descendant of a powerful family, but his status is much lower compared to Han Ji-won. He uses red flames.