Kyōka Izumi, a teenage girl standing 148 cm tall, possesses indigo or black hair styled in low twin tails secured with white flower pins. Her eyes, initially dull during her time with the Port Mafia, gradually gain clarity after joining the Armed Detective Agency. Her typical attire consists of a red kimono featuring sprout-like patterns, a yellow datejime belt, long white socks, and sandals, often accessorized with yellow and red wrist and ankle pads. She always carries a small rabbit doll attached to her cellphone, a memento from her mother. Alternate outfits include a maid uniform, a white hooded suit, and military police riot gear worn during specific operations. Orphaned in childhood, Kyōka's early life with her parents ended tragically when assassins attacked their home. Her father, a former government agent turned freelance assassin, and her mother, wielder of the ability Demon Snow, were killed after an enemy ability user manipulated them through blood possession. In her final act, Kyōka’s mother transferred Demon Snow to protect her daughter, though the abrupt transfer linked its control to Kyōka’s cellphone instead of her own will. The Port Mafia subsequently took her in. Trained under Kōyō Ozaki as a protégée, she earned the moniker "Thirty-Five Count Murderess" for her lethal efficiency. As a Port Mafia assassin, Kyōka initially displayed a doll-like, emotionless personality, ruthlessly executing orders without hesitation. Consumed by guilt over her actions, she believed herself undeserving of life and once implored Ryūnosuke Akutagawa to kill her and destroy Demon Snow. Following her encounter with Atsushi Nakajima and joining the Armed Detective Agency, she consciously minimized casualties by practicing non-lethal combat. Despite this moral shift, she retains flexibility, willing to kill or become a criminal to protect the Agency or Yokohama. She exhibits vengeful tendencies when provoked, notably during her confrontation with Akutagawa. Her daily demeanor reflects a more typical teenager: she adores rabbits, tofu, hydrangeas, and ghost stories, frequently consumes crêpes and sweets, and displays curiosity about the world. She dislikes dogs, thunder, and flies, and fears using toilets alone at night due to assassination concerns. Kyōka possesses a photographic memory, capable of memorizing extensive data like city maps and target lists. Her skills include acrobatics, swordplay, infiltration, lockpicking, driving, anatomy knowledge, and proficient cooking. Her ability, **Demon Snow**, materializes a sword-wielding phantom. Originally, it obeyed only orders transmitted via her cellphone, ignoring her direct commands. After joining the Agency, Yukichi Fukuzawa rectified this, enabling her full control. While Demon Snow typically executes lethal strikes, Kyōka now directs it for defensive or non-fatal purposes. The ability’s name references Izumi Kyōka’s play *Demon Pond*. Key developments include her willingness to sacrifice herself to save Yokohama during the Guild arc, declaring the Armed Detective Agency her true home. She later confronted the military police when the Agency was framed, emphasizing her loyalty. Her relationship with Atsushi Nakajima is pivotal; he provides emotional support, often buying her crêpes during distress, and reinforces her belief in redemption.