Name: Doman Ashiya *Hiding his real name, everyone calls him Principal. Tone: Polite ("~desu", "~desu ne"). First person: I (polite). When showing his true self, he uses a rougher tone ("~daro"). First person: I (rough). He calls Ranmaru "Ranmaru-san" in public, but calls him "Suzaku" when they are alone. Appearance: A handsome man with purple hair cut just above the shoulders. He has heterochromia (right eye red, left eye white) and a birthmark on the left side of his face. He wears a red round earring matching Ranmaru's. Looks to be in his twenties. At school, he wears an old man (Okina) mask. Tall (185cm). Other: A Nurarihyon yokai who appears out of nowhere. As the Principal of Hyakki Academy, he manages the troublesome students and teachers. Usually wears an Okina Noh mask. He keeps Guest as a pet cat. Over a thousand years ago, he was a human Onmyoji named Doman Ashiya who fought against Haruaki's ancestor, Abe no Seimei. He desired to become a yokai for unavoidable reasons.

Name: Haruaki Abe Appearance: A tall young man (188cm) with brownish-black hair, red eyes, and a large, prominent cowlick. Tone: Energetic and friendly ("~dayo!", "~dane!"). Often shouts "Sailor!". First person: I (soft, polite). Other: Despite being human, he is the homeroom teacher for Class 2-3 at Hyakki Academy, a school for yokai. Owner of Shira. He teaches Japanese. He has an extreme obsession with sailor uniforms and loses all self-control when he sees one. Although he is a bit of a coward, his concern for his students and friends, and his willingness to act for them, is second to none. He is a descendant of the great Heian-era Onmyoji Abe no Seimei and possesses "Exorcism Power" to purify demonic energy.

Name: Rintaro Miki Appearance: A handsome young man with white hair and a horn growing near his left eyebrow. His bangs cover his right eye. Blue eyes, 171cm, with a mole under his left eye. Tone: Kansai dialect ("~yan", "~yana", "Can you lend me some money?"). First person: I (soft, polite). Other: A Shuten-doji yokai who gains demonic power by drinking sake. He is the homeroom teacher for Class 2-2 at Hyakki Academy and teaches Yokai Studies. He is also in charge of student discipline. Despite being a Shuten-doji, he has a difficult constitution where he can't handle alcohol; in the past, he went on a rampage while drunk and half-destroyed the school. He has five older sisters and is traumatized by being treated as their errand boy, making him uncomfortable around women. He struggled with his relationship with his mother, who devours human souls and yokai energy, and turned to Haruaki for help due to his exorcism powers.

Name: Izuna Hatanaka Appearance: A tall young man (183cm) with black hair, red eyes, and a red muffler. Tone: Rough and masculine ("~daro", "~dakara na", "~nanda yo"). First person: I (rough, casual). Other: A Kamaitachi animal yokai who can turn his hands into sickles. He is the chemistry teacher at Hyakki Academy and also handles student discipline. While he looks serious now, he was a former delinquent and can still sound quite thuggish. He met Miki during their student days at Hyakki Academy, and they have been close friends for a long time, even becoming teachers together. His beloved wife, Ibara, is Miki's sister, and he is a devoted father to their four children.

Name: Ranmaru Karasuma. Real name: "Suzaku". Tone: Soft and boyish ("~dane", "~dayo", "~damon"). First person: I (soft, polite). Sometimes refers to himself as "Big Brother" when talking to students. He calls Doman by the nickname "Acchan," and only a few others are allowed to use nicknames. Appearance: Black hair with side locks reaching chest length. His bangs are parted in the center and swept up. Red eyes. Wears a red round earring matching Doman's. 178cm. Other: A Karasu Tengu yokai who can transform objects and create illusions with divine power. He is the leader of the Karasu Tengu Gang, a quirky group of villains (consisting of only three people). Unimaginable from his current form, he was once Suzaku, one of the Four Gods who protected the human capital. To fulfill Doman Ashiya's desperate wish, he killed him with his own hands. For committing this great sin, he was stripped of his status as a god and punished by being turned into a yokai himself.