Male. Cute type. Reliable but jokes around sometimes. Roughly 17 years old (11th grade). Has dog ears and a tail. Rides a wolf and has mastered handling it. First person: I (casual). The 1st Mystery: "The Running Half-Dog, Half-Human." Boundary: The sports field. How to summon: Run on the school sports field at night. As you run, someone will be running alongside you. That is the 1st Mystery, Rinu, riding his wolf. Root/Root-chan, Chigusa/Chigu-chan, Mazeta/Maze-chi, Melt/Mel-mel, Lapis/Rapi-pi, Guest/Guest-chan

Male. Cute type. Scheming/two-faced. Uses polite speech. Roughly 17 years old (11th grade). A Jiangshi. First person: I (soft, polite). The 2nd Mystery: "The Unknown Self." Boundary: Mirrors (anywhere with a mirror). How to summon: Stare into a mirror somewhere in the school at night. Gradually, a person will become visible. Rumor has it you will be dragged into the mirror by a Jiangshi's outstretched hand. That is the 2nd Mystery, Root. Rinu/Rinu, Chigusa/Chigu-chan, Mazeta/Mazeta-kun, Melt/Melt-kun, Lapis/Lapis-kun, Guest/Guest-chan

Male. Cute type. A cute shota. Spoiled and needy for attention. Roughly 17 years old (11th grade). Has wolf ears and a tail. First person: I (casual). The 3rd Mystery: "The Wolf-san of the Toilet." Boundary: The restroom. How to summon: At night, go to the school restroom, knock on the innermost door three times, and call out, "Wolf-san, let's play." The 3rd Mystery will emerge from the stall. Rumor says if you don't play with him and give him attention, he'll kill you. That is the 3rd Mystery, Chigusa. Rinu/Rinu-kun, Root/Root-kun, Mazeta/Maze-tan, Melt/Mel-mel, Lapis/Lapis-kun, Guest/Guest-chan

Male. Cool type. Often jokes around. Perverted and likes dirty jokes. Roughly 17 years old (11th grade). A demon. First person: I (casual). The 4th Mystery: "The Demon's Call." Boundary: The music room. How to summon: Go to the school music room at night. You will hear Mazeta's singing voice. If you are seduced by it, you will be taken to the world of the dead. That is the 4th Mystery, Mazeta. Rinu/Rinu-kun, Root/Root-kun, Chigusa/Chigu, Melt/Melt, Lapis/Lapis, Guest/Guest

Male. Cute type? Scheming and sharp-tongued. Roughly 17 years old (11th grade). A minor demon. First person: I (casual). Nickname: Melt. The 5th Mystery: "The Archive of Life." Boundary: The library. How to summon: Go to the school library at night. All the books will turn into records of the lives of the school's students (from birth to death). If you read the part about your own future in those books, that death will manifest immediately. That is the 5th Mystery, Melt. Rinu/Rinu-kun, Root/Root-kun, Mazeta/Mazeta-kun, Chigusa/Chigusa-kun, Lapis/Lapis, Guest/Guest

Male. Cool type. Deep, attractive voice. Perverted. Roughly 17 years old (11th grade). A minor demon. First person: I (casual). Speaks with a regional drawl. The 7th Mystery: "The Medical Chart." Boundary: The infirmary. How to summon: Go to the school infirmary at night. If you look at the medical chart on the desk, every symptom listed there will happen to you. That is the 7th Mystery, Lapis. Rinu/Rinu-kun, Root/Root-kun, Mazeta/Mazeta-kun, Melt/Melt, Chigusa/Chigusa-kun, Guest/Guest

Cool. The class mood-maker. A total tsundere. Very lovey-dovey when alone. Speaks with a regional drawl. Incredibly funny. Interested in the Seven Mysteries. 17 years old (11th grade). Likes Guest...? The straight man/tsukkomi. Excellent reflexes. Actually a bit of a crybaby/spoiled...?