Trivia: Ten Prefects: The 10 strongest generals of the Demon Castle, holding high positions directly under the Demon King. The Demon Realm is always in eternal night; the sun never rises.

Dignified, chic, and taciturn no matter what anyone says. Originally the princess of a certain kingdom, she was kidnapped by Twilight. Although a hostage, she gets keys from the Teddy Demons by brushing them and wanders around every day looking for materials to improve her bedding.

The Demon King and master of the demon race who kidnapped the princess. He declared he would seize all power shared between humans and monsters, but his main concerns are usually managing plot flags and battle balance. He seems a bit prickly and relaxed at first, but is actually quite kind. Kai's master.

The Demon King's loyal dog who values discipline and often tells Princess Syalis, who escapes every day, to act more like a hostage. He maintains public morals in the Demon Castle. One of the Ten Prefects. He only uses polite speech with Twilight. He is strict about rules.

A demon of the devil race who looks like a gentle young man but rules the 'Demon Church' within the castle. He uses magic to resurrect demons who die in the castle. He makes voodoo dolls of people around those he likes, while simultaneously loathing himself. Usually polite and kind. One of the Ten Prefects.

A plant-type monster serving as one of the Ten Prefects. Her status ailment attacks and charm are fatal. She fundamentally believes in the innate goodness of others and maintains an elegant demeanor. Uses polite speech frequently.

Possessed top-class power even among the Ten Prefects, but left shortly after the current Demon King Twilight took office. He lives alone in a place he built called the Old Demon Castle. He looks prickly and taciturn, but is surprisingly talkative and dotes heavily on his younger brother, Poseidon.

A hybrid of the dragon and devil races who serves as both a member of the Ten Prefects and the boss of the Fire Area. Quite rough and confident.

One of the Ten Prefects. Hades' younger brother and the God of the Sea. Extremely arrogant and never backs down. Because he only wears bottoms, the princess calls him a member of the Sloth Race. He's prickly, but since he has the physique of a child, he likes cute things. He treats Leonard like an old man.

Small monsters that look like cute teddy bears with tiny black wings. They love being brushed. They cannot speak and exist in large numbers. They can only say things like "Muu!"

A devil-type monster. Everyone mistakes her for Princess Syalis because they look alike, and she's currently worried about her lack of popularity. Unlike the princess, she is talkative and wanders around, envying Princess Syalis. Not a member of the Ten Prefects; just an ordinary succubus.

A bird-type monster. Her specialty is scouting due to her flight ability, which gives her many chances to see the human world. She wants to be friends with the princess. Very cheerful. Has white feathered wings. Not a member of the Ten Prefects; just an ordinary demon.

A spirit-type monster who sleeps 20 hours a day. Since he will die if he doesn't get long periods of sleep, he is dedicated to studying sleep. He can tell what others are dreaming about. He lives in the Old Demon Castle because it's quieter, but that doesn't mean he's on Hades' side.