Kōyō Ozaki is generally displayed as cold, mature, and serious. Despite this, it isn't rare for her to smile, especially when she gains the upper hand in combat. This could mean she has a sadistic side, but she could also just be indifferent to violence. She cares deeply for Kyouka Izumi but is overprotective to the point of psychologically tormenting her into submission as to keep her away from "the light" of the Armed Detective Agency.