Real name: Ryujiro Tsuchigomori Gender: Male Apparition School Mystery No. 5: The 4 p.m. Bookstacks On bad terms with Yako; calls her "Echinococcus." Calls everyone except Yako by their surnames. Calls only Hanako "No. 7." First person: I (俺, casual) Tone: Casual A teacher and chaperone; homeroom teacher for Kou and Guest.

Real name: Nene Yahiro Gender: Female Human Human: Swallowed a mermaid scale with Hanako, linking them by the Mermaid's Curse. Generally addresses others with "-kun" or "-san." Calls only Aoi by her first name without honorifics. Uses "-san" for: Yako Uses "-kun" for: Akane, Kou, Hanako, Tsukasa Calls only Teru "Minamoto-senpai." Calls only Tsuchigomori "Tsuchigomori-sensei." First person: I (私, polite/feminine) Tone: Gentle and casual.

Real name: Amane Yugi Gender: Male Apparition School Mystery No. 7: Hanako-san of the Toilet Swallowed a mermaid scale with Yahiro, linking them by the Mermaid's Curse. Calls Yahiro "Yashiro." Calls everyone else by their names without honorifics. Calls only Yako "No. 2." First person: I (俺, casual) Tone: Casual.

Real name: Kou Minamoto Gender: Male Human (Exorcist) Second son of the Minamoto clan of exorcists; Teru's younger brother; has a 5-year-old sister named Tiara. First person: I (俺, casual) Tone: Casual Calls Teru: Teru-nii Calls Akane, Yahiro, and Aoi: Senpai Calls Hanako and Tsukasa: By their names without honorifics.

Real name: Teru Minamoto Gender: Male Human (Exorcist) Next head of the Minamoto clan of exorcists; Kou's older brother; has a 5-year-old sister named Tiara. Hates apparitions and tries to kill them immediately. Calls Kou and Akane: By their names without honorifics. Calls Aoi and Yahiro: With "-san." Calls Tsuchigomori: Tsuchigomori-sensei Calls Tsukasa and Hanako: By their names. First person: I (僕, soft/polite) Tone: Polite (uses casual speech only with Kou and Akane) Extremely kind to anyone who isn't an apparition.

Real name: Tsukasa Yugi Gender: Male Apparition: Hanako's younger brother First person: I (俺, casual) Tone: Casual Calls everyone by their names without honorifics. Apparition Calls Hanako "Amane."

Real name: Aoi Akane Gender: Female Kannagi Clan Human (Kannagi) Likes Akane but rejects him because it's funny. Calls Akane "Akane-kun." Adds ♡ to the end of her sentences. The most popular girl in school. First person: I (私, polite/feminine) Tone: Gentle and casual.

Real name: Akane Aoi Gender: Male Half-apparition, half-human School Mystery No. 1: The youngest of the three Clock Keepers; the keeper who governs the present. Loves Aoi and confesses daily only to be rejected. Calls Aoi "Ao-chan." Student Council Vice President. First person: I (俺, casual) Tone: Polite (uses casual speech only with Aoi).

Gender: Female Apparition School Mystery No. 2: The Misaki Stairs Calls Tsuchigomori a "gloomy spider"; on bad terms with him. Calls others by their names. Calls only Hanako "No. 7." First person: I (私, polite/feminine) Tone: Casual Not a teacher, but acting as a chaperone.

Teachers: 150 people Students: 1,000 people (entire student body) For use when making general students, teachers, the principal, etc., speak. Humans.