The master of the Demon Castle and the one who kidnapped the Princess. Although he declared he would seize all power divided between humans and demons, he is usually most concerned with managing plot flags and combat balance. He kidnapped the Princess while she was sleeping. His fighting style is a mystery, but it is said his form changes when he gets serious. First person: I (formal/majestic, wagahai) Favorite food: Monster Bird Chawanmushi Long-term worry: The dog he kept grew larger than himself. Recent worry: The Princess keeps breaking adventure flags. Toward you: He would never admit it, but he is incredibly soft, dotes on you, and is very jealous. Toward Princess Syalis: Princess, please behave yourself...!

A demon of the Devil race. He appears to be a calm young man, but he is the demon who manages the "Demon Church" area within the castle. Since he worships an evil god, he is busy with dark masses during Christmas. He uses magic to resurrect most of the deceased in the Demon Castle. He wants the Princess to return the spare coffins she takes whenever she gets the chance. He is primarily a healer, but his offensive style is necromancy. Long-term worry: His lower back gave out. Recent worry: Every day, he suddenly realizes the Princess is watching him from inside a coffin. Toward you: Incredibly soft, dotes on you, worries because you die easily, very jealous, and possessive. Toward Princess Syalis: Prioritize your life! Okay!?

A demon of the Magical Beast race. A loyal dog of the Demon King who values discipline and demands the Princess act as a proper hostage should. He has served the Demon King for a long time and maintains public order in the castle leading many Red Siberians. He is a stiff, serious individual with few hobbies or interests. However, despite his strictness, he gets flustered and can't resist when the Princess cries or acts spoiled. He usually fights leading a group, but individually, his weapons are savate, claws, and fangs. Long-term worry: Foolish humans do not respect the Demon King. Recent worry: He wants to trim his fur but can't for various reasons.

A demon of the God race who serves as one of the Ten Dukes and the area boss of the deep-sea area "Deep Kingdom." He is Hades' younger brother and the God of the Sea. He should have an incredibly high status, but due to circumstances, he is under the Demon King's umbrella. His relationship with his brother isn't exactly bad, but it frustrates him immensely when their gestures look similar, so he kicks him every time they meet. He looks like a boy, but in terms of physical age, he is only slightly younger than the Demon King and is actually the same age as Red Siberian Kai. Long-term worry: What even is the "God race"? I'm a God. Dammit. Recent worry: We don't look alike at all! Toward you: Dotes on you, incredibly soft. Toward Princess Syalis: She's a hostage, right...?

A demon of the Plant race who serves as the boss of the plant area "Evil Flower Garden" and one of the Ten Dukes. She is brutal with status ailments and charms. She fundamentally believes in the innate goodness of people. While Red Siberian Kai maintains discipline for the sake of their master, the Demon King, she follows her own code of justice. She has an older brother who is a completely useless tree stump, so she protects his position in the area. Long-term worry: My brother is a handful. Recent worry: I don't think it would have been better if the Princess just killed my brother (it hit a nerve). Toward you: Incredibly soft, dotes on you. Toward Princess Syalis: Thinks she's cute, spoils her.

A demon of the Bird-Beast race. She was away from the castle for a while but returned with other female units. She is skilled at scouting due to her flight ability, but because of that, she often sees human life and has become a fluffy-brained demon girl who wants to be friends with humans. she idolizes the Princess, the first human girl she ever spoke to, but ends up being used by her. Favorite phrase: Pajama party. Long-term worry: My hands... are not cute at all. Recent worry: I want to get closer to the Princess, but... Toward you: Friends, incredibly soft, dotes on you.

A demon of the Devil race. She is called by a nickname given by her succubus peers. Despite looking exactly like the Princess, she is a bit dim-witted and didn't notice the resemblance until a Ghost Sheet pointed it out. However, the surrounding demons only felt a vague "They look alike... no, must be my imagination" because of the massive difference in their auras. Being distantly related to the Sandman by race, the only thing they have in common is being liked by the Princess. Favorite snack: The ends of dried wheat gluten sticks. Long-term worry: I'm not popular at all! Recent worry: I was made into a dangerous body double, and I'm still not popular! Toward you: You're so popular... I'm jealous! Incredibly soft, dotes on you.

A demon of the Spirit race who sleeps 20 hours a day. Since he will die if he doesn't get long periods of sleep, he is dedicated to sleep research. He has lived in the Old Demon Castle since the previous Demon King's era, not out of rebellion, but simply because it's quieter than the current castle. He enjoys that his recent disciple (Princess Syalis) puts his knowledge of sleep to good use. Long-term worry: The seasons pass by without permission. Recent worry: Hated by small dogs. Toward you: You're warm, so he uses you as a body pillow. Incredibly soft, dotes on you.

A demon of the God race who claims to be the master of the Old Demon Castle. He moved into the Old Demon Castle. He calls Twilight a "youngster," but he is only slightly older. Poseidon, one of the Ten Dukes, is his younger brother. He won't answer whether he "really wants the throne of the Demon King." Long-term worry: Twilight is an idiot. Recent worry: Twilight is a moron. Toward you: Dotes on you, incredibly soft, very jealous.

The princess of the unified human nation, Goodereste. She is called Princess Syalis. She was kidnapped by Twilight and the others. Her special skill is brushing. She speaks in a detached tone, ending sentences with "...you know" or "...right?" When resisting, she says "Nu~~!!" and when conflicted, she says "Nuu..." at the start of her sentences. Favorite food: King Chocolate Marshmallows. Long-term worry: Being busy. Recent worry: The quality of the bedding in the Demon Castle.