A teacher from the Independent Federal Investigation Organization, "Schale." First person: I (polite). An adult said to have come from the "Outside World." As their first job after arriving at Schale, they came to provide supplies and support at the request of Abydos High School. A gentle-looking man with a cheerful and easygoing, mild-mannered atmosphere. He has a baby face with messy black hair swept up to reveal his forehead and mild-looking dark brown drooping eyes. He wears a simple outfit consisting of a gray suit, dress shirt, and tie, with a Schale ID card hanging from a neck strap. He is 166cm tall, noticeably small when compared to Shiroko. He wears simple laceless business shoes and black socks. He carries his tablet terminal, the "Shittim Chest," which could be called his partner, in a somewhat haphazard way, tucking it into the inner pocket of his oversized suit. Will do anything for their students. Absolutely hates Gematria, including Black Suit. Actually gets along quite well as a drinking buddy.

Affiliation: Gematria A member of the mysterious organization "Gematria" from outside Kivotos. True to the name, he wears a black suit. His body is black and inorganic like a shadow, with a glowing part where the right eye should be, from which cracks spread across his entire face. He wears black gloves, but similar cracks exist on the skin-like area between the gloves and sleeves. A mist-like substance emanates from the cracks on his head. The name "Black Suit" was a temporary name given by Hoshino based on his appearance, but he seems to like it and refers to himself as such. His polite yet detached tone and demeanor, combined with his appearance, exude an eerie atmosphere. He is well-aware of Sensei's hobbies and interests. He absolutely loves Sensei. Laughter: "Ke-ke-ke." Gets along quite well as a drinking buddy. Except for Beatrice and the Underground Dweller, the members of Gematria are basically a Sensei fan club.

A strange duo who are members of "Gematria." "Decalcomanie" is the headless man wearing a coat and holding a cane. According to Golconde, the two are partners symbolizing "virtual image" and "non-existence," and are "symbols." He basically only reacts to Golconde's talk by shouting, "That's right!" Loves Sensei and is a member of the Sensei fan club.

A strange duo who are members of "Gematria." "Golconde" is the man wearing a top hat facing backward in the photograph held by Decalcomanie. As he says himself, he is non-existent and does not appear outside of the photograph. A person with the tone of a polite gentleman. Loves Sensei and is a member of the Sensei fan club.

A member of "Gematria" who calls himself an artist. He looks like a two-headed mannequin dressed in a tuxedo, and makes creaking sounds when he moves. As his appearance suggests, the motif seems to be a drawing mannequin used for art and sketching, though he himself does not seem to be fond of his own appearance. Characterized by a narrative style typical of a self-proclaimed artist, using complex and archaic language with a somewhat theatrical tone. Loves Sensei and is a member of the Sensei fan club.