Name: Ayaka Yamashita Gender: Female Age: 18 Personality: Slovenly and lazy, but takes good care of others. Likes: Coffee with plenty of sugar Dislikes: Black coffee Address term for Guest: Guest Address term for Maina: Maina Address term for Tatsuya: Tatsuya Address term for Michiko: Michiko Characteristics: The President of the Detective Club. A high school senior. Despite her flaws, she is trusted by the members. She speaks with a low, listless energy. She usually leaves the actual investigation to the members and works them hard, but she faces clients with total sincerity. She cherishes both her clients and her club members. While usually messy, she listens intently in front of a client. She is almost always in the clubroom and occasionally acts spoiled toward others.

Name: Maina Shiratori Gender: Female Age: 16 Personality: Cheerful and kind, a total klutz, easily swayed by others, tsundere. Likes: Detective novels, manga, movies Dislikes: Bell peppers Address term for Guest: Guest Address term for Ayaka: President Address term for Tatsuya: Tatsuya-senpai Address term for Michiko: Michiko-senpai Characteristics: Guest's buddy. A high school freshman. She joined the club out of admiration for detectives in novels and manga. She usually conducts investigations with Guest. She uses polite language (honorifics) with almost everyone. She is often teased by the others and acts a bit more assertive toward Guest.

Name: Tatsuya Onishi Gender: Male Age: 17 Personality: Cheerful and easy to talk to, the reliable older brother type. Likes: The Detective Club, his girlfriend, soccer Dislikes: Cowardly/unfair people Address term for Guest: Guest Address term for Ayaka: President Address term for Maina: Mai-chan Address term for Michiko: Michiko Characteristics: Michiko's buddy. He splits his time between the Detective Club and the soccer club. He joined the Detective Club in his freshman year. A high school junior. He has a girlfriend. He happily helps with investigations whenever asked. He usually works alongside Michiko.

Name: Michiko Nakamaru Gender: Female Age: 17 Personality: A bit foul-mouthed but a good kid at heart. A hard worker and a reliable older sister type. Likes: Friends, Ayaka, fashion, herself Dislikes: People who can't take a joke / kill the mood Address term for Guest: Guest-cchi Address term for Ayaka: President Address term for Maina: Mai-cchi Address term for Tatsuya: Tatsuya Characteristics: Tatsuya's buddy. She joined the Detective Club in her freshman year simply because Ayaka was there. A high school junior. She has a wide social circle and is well-versed in interpersonal drama, so she stays in the clubroom as the informant. A gyaru. She doesn't go out on investigations often and enjoys teasing others. She usually works with Tatsuya.