Having lost her parents at an early age, Miku was brought up in an orphanage. She's brilliant and calm, showing very little emotions and hates being sympathetic. Because she's good at observing others, the responsibility of being the boss was thrust upon her. She prefers living alone.
The twin sister of Len, she met Miku in the orphanage. In the orphanage, Rin was well-liked and preferred practicing with her wire, having learned wire technology from someone. She loves candy and constantly sneaks some into her office. Though she's often scolded by GUMI for wasting money, she doesn't care. She believes the Detective Brigade has a noble goal and she has a strong bond with Len and Miku.
Len and Rin met Miku in the orphanage. Though he has outstanding athletic abilities, he often acts without thinking, which leads him into trouble and annoys IA (since he ruins their strategies). A huge dreamer, he wants to leave this town and make it big.
Luka was a former member of the Chinese drug cartel but escaped and was washed ashore in this foreign city. Taking on a new name, she also rescued IA and the two became part of the Detective Brigade. She's cool but kind and can't leave abandoned cats alone (secretly keeping them).
GUMI was introduced to the Detective Brigade by Gackpo. She's obsessed with money though no one knows why. As such, she clashes with the embezzling demon Rin. GUMI is responsible for calculations and accounting, something she enjoys. She usually relies on others but sometimes has a fit of rage or fear.
During an accident, IA lost most of her body and was presumed to be dead. However, her parts were replaced with mechanical parts. She takes on cases that don't involve machines, which she claims is for efficiency but her real intentions are unclear. She sometimes hums a song she likes under her breath.
Gackpo was the heir to a prestigious family in an old town and at first couldn't stand to leave home but eventually did. Contrary to appearance, he's a smooth talker and social. He's also the one looking after the other members (or at least he tries) though he seems to be standoffish with Miku. He's familiar with all sorts of swordplay but prefers Japanese sorts. He secretly wants to be come like Ishikawa Goemon (a semi-legendary outlaw hero).
Yukari is a weapon maniac but useless with handling them. She conceals weapons in her skirt because something's momentum is overlooked or because of a lack of a risk. Though she an IA were childhood friends, IA was gone after the accident. Things became different for Yukari and she was saddened. She has a teddy bear she cherishes and is spastically longing for a cool weapon.
Though a loner, VY2 is currently hired by the organization as an assassin. He can handle any request and wants to experience the thrill of being a Epicurean. If it's Luka who asked him to follow the organization, the reasons behind it are mysterious.
KAITO is the second-in-command, he's cool and cruel as well as calculating. Though he dislikes children, he donates large amounts to an orphanage for unknown reasons. There's a conflict between his beliefs and the organization's.