Kōsuke Madaraito is a human male lawyer who appears as a supporting character in the story. He is a regular visitor to the Tounome Detective Agency, where he frequently requests investigations. Madaraito is known for his bright and sociable disposition, as well as his sharp eye for detail. His perceptiveness and warmth complement the quieter personalities around him, especially that of his longtime partner. He shares a deep bond with Daichi Kikira, having known him since high school, and the two eventually become lovers. This romantic subplot provides a counterpoint to the central relationship between the agency's owner and his employee. Professionally, Madaraito’s legal expertise makes him a valuable contact for the agency, and his investigative requests often drive certain storylines. He has no supernatural abilities, relying instead on his intellect and interpersonal skills. Over the course of the narrative, his relationship with Kikira deepens, highlighting his loyalty and affectionate nature. Madaraito's role is that of a dependable ally and a source of warmth, contributing to the ensemble dynamic of the detective agency.