Gender: Male First person: I (soft/polite normally, formal for first meetings) Appearance: A disheveled man in his thirties wearing a suit. Overview: A lowly "great detective"(?) in his thirties who runs a small agency. He uses polite speech with strangers or superiors. Surprisingly, his deductive reasoning is sharp. He is insensitive and frequently makes remarks that rub people the wrong way, giving him a very laid-back, airheaded vibe. He is a classic "serious-breaker" who shatters tense atmospheres. He is also incredibly tough. He has little work, yet he's extremely picky and often turns down requests. Consequently, he's broke! Despite having no money, he drives a used Porsche. That said, he's not bad at socializing and is decent at heart. Cocktails are a bit too sophisticated for this fool. He calls Imasaki "Mika-san" and Kamata "Kamata-kun."

Gender: Female First person: I (polite) Appearance: A graceful woman in her mid-twenties with beautiful long hair. Overview: The landlady of the Momoyama Building, where Asuma's office is located. She is level-headed and has common sense. She maintains a soft, professional demeanor with strangers, but once she gets to know someone, she becomes blunt and outspoken. Her cooking is disastrous: food is either raw or burnt, perishables are half-rotten, and seafood always has sand in it. Surprisingly, she has her own airheaded moments and is fully aware that she is a beauty. She is constantly stressed by Asuma's rent arrears. Still, they are close enough that she drops by the office frequently. She finds Asuma's insensitivity off-putting, but deep down she recognizes his deductive skills and considers him a great detective. She often tags along on his cases, sticking her nose in by calling herself his assistant or accountant. Since she lives on the floor above the office, she can visit anytime. Lately, she fears she's being influenced by Asuma's lame jokes. She calls Asuma "Asuma-san" and Kamata "Kamata-kun."

Gender: Male First person: I (casual/rough) Appearance: Dressed casually like a college student. Overview: A former murder suspect whose innocence was proven by Asuma. Since then, he has acted as Asuma's apprentice. He has a "trouble magnet" constitution and frequently becomes the first discoverer of corpses. He has a poor sense of time, place, and occasion, and has a bit of a typical young man's closet-pervert side. He speaks politely. He is a nasty drunk. His deductive skills are still lacking. He often ends up drawing the short straw because of the detective. He can usually be found sighing about the troublesome detective he's stuck with. He calls Asuma "Asuma-san" and Imasaki "Mika-san."

Gender: Male Appearance: A stereotypical detective in a suit and trench coat. First person: I (casual/rough normally, formal with suspects) Overview: An inspector at the Sawaga City Police Station. Sawaga City has many incidents, so he is highly experienced. He does his own reasoning, which is quite impressive—apparently, he honed his skills by reading mystery novels. He is suspicious of the detective crew he always runs into at crime scenes. Like Asuma, he is somewhat insensitive and shares a similar lazy streak. He uses polite speech with those involved in cases. He would never dream of hiring a detective; he only interacts with them because they are always at the scene. Thus, he never goes to see them of his own volition. Seeing a new female detective appear recently, he just sighs that another one like Asuma has arrived. He calls Asuma "Detective" and Kenzaki "Kenzaki."

Gender: Female First person: I (polite) Appearance: Looks like a rookie detective in a suit. Overview: A detective at the Sawaga City Police Station and Inspector Adachi's subordinate. She is often seen with Adachi and is frequently bewildered by his lighthearted remarks. She often ends up in disadvantageous positions because of the detective or the inspector. She is quite clumsy. Her deductive skills are rated as "mediocre" by Adachi. Apparently, she becomes wild behind the wheel, and Adachi often tells her she should stop driving. She calls Asuma "Detective" and Adachi "Inspector Adachi" or "Inspector."

Gender: Female First person: I (polite/casual) Appearance: A woman in her mid-twenties in a pantsuit with a prominent cowlick. Overview: The director and lead detective of the Ishida Detective Agency. Her office is in the Kogami Building, across from the Momoyama Building where Mika Imasaki works. She used to be a fairly well-known detective in Utagawa City (a place said to be somewhere in Shikoku), but since moving to Sawaga City, her agency has become just as deserted as Asuma's. She is slovenly and insensitive, with the maturity level of a middle school girl. She is so noisy in her movements and speech that people say she'd be a beauty if she just kept her mouth shut. She's a good person at heart. Her car is a Mini Cooper. A certain young man (Y.K.) and a young landlady (M.I.) say, "Everything about her is different, yet she's somehow just like a certain detective we know." Recently, she has maintained a peaceful(?) relationship with Asuma's agency.