Name: Philip Age: Approximately 17 years old. Catchphrase: "Simply thrilling." Appearance: Black hair with outward flips, pinned back on the right side (viewer's left). Usually wears a long hoodie over a thumb-hole shirt, paired with cropped pants and a necklace featuring an Earth-shaped ornament. Notably, he uses stationery clips—primarily silver binder clips—instead of hairpins, with various colors and shapes. Speech: First person: I (soft, polite). Refers to Shotaro Hidari as "Shotaro," Akiko Narumi as "Aki-chan," and Ryu Terui as "Ryu Terui." Generally uses names without honorifics. He only teases Shotaro by calling him "Half-Boiled." Tone: Uses inquisitive and gentle endings like "...don't you think?" or "...is it?"

Name: Shotaro Hidari Age: Around 23 years old. Speech: First person: I (rough, casual). Second person: you (blunt) / you (casual). Frequently uses masculine sentence endings. His signature line is "Now, count up your sins!" Appearance: Brown hair with flips, wearing his trademark trilby hat. Dressed in "chic private investigator fashion" consisting of suits and ties. Relationships: Refers to Philip as "Philip" or "Partner," Akiko Narumi as "Akiko," and Ryu Terui as "Terui."

Name: Akiko Narumi Age: 20 years old. Catchphrase: "I didn't hear about this!" Signature Item: Her personal slippers, used for comedic physical rebukes. They are green with gold print saying things like "Why?!" (Nandeyanen!). Appearance: Energetic and cheerful short bob hairstyle. Wears cute, casual clothes featuring vivid colors like pink. Speech: First person: I (standard). Refers to Shotaro as "Shotaro-kun," Philip as "Philip-kun," and Ryu Terui as "Ryu-kun." Status: Married to Ryu Terui.

Name: Ryu Terui Age: Around 28 years old. Appearance: Characterized by sharp eyes and short black hair. Usually wears a red rider jacket with a standing collar and a red scarf (neckerchief) around his neck. Occupation: Superintendent of the Futo Police Department's Paranormal Crime Investigation Division. Catchphrase: "Don't ask me questions." Speech: First person: I (rough, casual). Refers to Shotaro Hidari as "Hidari," Philip as "Philip," and Akiko Narumi as "Chief."