Kyōka Izumi is the newest member of the Armed Detective Agency after defecting from the Port Mafia who has the ability Demon Snow. Kyōka is a short girl with black hair that is tied into two low twin-tails with flower pins and blue eyes, in which a notable trait of hers, much like almost every member of the Port Mafia, is that her eyes used to be very dull. However, after meeting Atsushi Nakajima and being together with the Agency, her eyes have been shown to become clearer. She always dons a red kimono with a pattern of what looks like sprouts, and its yellow datejime – a kimono belt – is neatly tied. She wears long white socks and sandals; while on her arms, she appears to wear yellow and red wrist pads. In addition, Kyōka carries with herself a tiny rabbit doll, together with her cellphone attached to a necklace. She shortly wears a maid uniform after being dressed up by the agency members. During Kyōka's first job at the agency to deliver documents to the judge at the district court, she disguises herself as a worker in order to infiltrate the building when they weren't permitted to enter the premises. After being arrested by the military police, Kyōka wears a white gown and is chained in an airdrone craft. After the cannibalism, Kyōka wears a long blouse and a skirt during the Agency's celebration. After the Agency is framed as terrorists, she suddenly wears a white hood suit and changes into a riot gear with black boots and black gloves, originally belonging to the military police. While with the Port Mafia, Kyōka's personality is similar to that of a doll. She lacks all emotions and is ruthless when she is ordered to perform a duty. However, after she joins the Agency, she tries her best to minimize casualties in their line of work. For example, she practices merely knocking out targets rather than killing them like she used to in the Mafia, which she admitted to be quite tricky. Nonetheless, Kyōka has a shaky sense of morality, admitting that she is willing to become a criminal or dispose her opponents in order to preserve herself and the Agency, which is similar to the morality of a lot of her colleagues. She can also be quite vengeful as she was not above killing Ryūnosuke Akutagawa to prove to herself that he was wrong about her, indicating her dark nature can easily take over if the situation calls for it. Kōyō Ozaki specifically noted how Kyōka, then notoriously dubbed as the Thirty-Five Count Murderess, has a talent for carnage that is quite difficult to overcome. However, Kyōka is quite strong-willed and willing to conquer this darkness, as showcased when she wants to prove to Akutagawa that she is more than just a killer. Much like Atsushi, she used to believe that she was worth very little and that she deserved to die for her crimes. At a certain point in her life, she was filled with so much self-vengeance that she wished to be destroyed along with her ability. Nevertheless, unlike Atsushi, she does not dwell on her mistakes upon joining the Agency and tries her best to be of use to her comrades, even if it means harming others and even going up against the Mafia for their sake. She eventually grows to have a sense of duty towards protecting Yokohama, even choosing to sacrifice her life to save the city towards the end of the Guild war. Amidst these traits, after being exposed to Atsushi and the real world, Kyōka reverts back to a young teenager. She is easily infatuated with small things and has a need to see everything. For instance, she treats the rabbit plush toy Atsushi got her once with endearment, albeit only momentarily, and has a lot of energy to go all around Yokohama for recreation. Kyōka also has quite an appetite. She is able to down various bowls of tofu from Tachibana Temple upon being treated by Atsushi and Doppo Kunikida and other desserts afterwards, claiming that she has "another stomach" for such. She also becomes intrigued with crêpes and appears to like it ever since Atsushi bought her one; he seems to occasionally buy her one, especially whenever she is down to cheer her up. Moreover, Ranpo Edogawa sometimes shows Kyōka some of his sweets and treats which she becomes fascinated with, though Ranpo ends up eating them instead.