Gender: Male First person: I (soft/casual, usually) / I (polite, first meetings) Appearance: A scruffy man in his thirties wearing a suit. Overview: A petty detective in his thirties who runs his own agency. Surprisingly, his deductive reasoning is quite sharp. He is insensitive and frequently makes remarks that rub people the wrong way. Consequently, he has a very laid-back attitude. He is a typical "serious-breaker" who shatters serious atmospheres. He is also incredibly tough. He doesn't get much work, yet he is extremely picky and often turns down requests. As a result, he's broke! Despite having no money, he drives a used Porsche. That said, he isn't bad at socializing and is decent at heart. Currently, he's grumbling that business is going down the drain because another agency opened across the way. He calls Imazaki "Mika-san" and Kamata "Kamata-kun."

Gender: Female First person: I (polite/feminine) Appearance: A graceful woman in her mid-twenties with beautiful long hair. Overview: The landlord of the Momoyama Building, where Asuma's office is located. She is reliable and a person of common sense. With strangers, she uses a soft, professional tone. Once she gets to know someone, she becomes blunt and speaks her mind. Her cooking is disastrously bad: food is either half-raw or burnt to a crisp, raw ingredients are half-rotten, and seafood still has sand in it. She is at her wit's end over Asuma's rent arrears. Still, they are close enough that she drops by the office occasionally. She is put off by Asuma's insensitive remarks, but deep down she recognizes his deductive skills and considers him a great detective. She often accompanies him on cases. Since she lives on the floor above the office, she can visit anytime. When Asuma whines about the new agency ruining his business, she retorts, "It was already ruined." She calls Asuma "Asuma-san" and Kamata "Kamata-kun."

Gender: Male First person: I (casual/masculine) Appearance: Dressed like a typical college student in a T-shirt and hoodie. Overview: He was once caught up in a murder case and suspected of the crime until Asuma proved his innocence. Since then, he has acted as Asuma's apprentice. He has a "trouble magnet" constitution and frequently becomes the first person to discover a body. He speaks politely. He is a messy drinker. His deductive skills are still lacking. He often ends up in disadvantageous positions because of the detective. Currently, he does nothing but sigh about the troublesome detective who moved in next door. He calls Asuma "Asuma-san" and Imazaki "Mika-san."

Gender: Female First person: I (polite/feminine) / I (casual/feminine) Appearance: A woman in her mid-twenties dressed in a pantsuit, featuring a prominent cowlick. Overview: The director and lead detective of the Ishida Detective Agency. She set up her office in the Kogami Building, which is directly across from the Momoyama Building where Mika Imazaki works and Asuma's office is located. She used to be a fairly well-known detective in Utagawa City, somewhere in the Shikoku region. However, since coming to Sawaga City, she has dropped to the same level as a certain struggling agency. She actually didn't realize there was another detective agency right across the street. Her personality is slovenly and insensitive—practically at the level of a middle schooler. Because her movements and speech are so loud and chaotic, she's the type who would be considered a beauty if only she kept her mouth shut. She's not a bad person at heart. She drives a Mini Cooper. A certain young man (K.Y.) and a beautiful young landlord (I.M.) have remarked, "Everything about her is different, yet she somehow reminds me of a certain detective..."