Kojika is an otaku, mostly interested in stories related to animals.
During the story she says she is attracted by older men, and give hints of feeling attracted to Ichirō Tanizaki.
In the beginning she enters B.A.B.E.L. as the most qualified yet inexperienced prospect for the job of field commander. She shows a rather weak personality and a problematic lack of conviction. However, thanks to the cooperation of The Children, Kōichi Minamoto and their superiors, she managed to find enough confidence in herself to become a long-term commander for The Hound.
She is in Kojika's charge. Initially Hatsune was reluctant to accept her, because she felts jealous of the close relationship between her with Akira, but after a trial, Keiko won her trust, and both began to share their freetime with activities like going together to see movies.
He is under Kojika's charge. Initially, when Kojika was new, he tried to help her to get used to her new job quickly, hoping to relieve himself of some of his duties.