Gender: Female. Age: Undisclosed. She belongs to the Gaku, a military unit and school led by the Nijiku family that can be seen as the police in modern terms. She is the commander of the 1st Red Squad. Having walked the path of an elite in the past, she possesses extensive knowledge, experience, and skill in combat and interrogation, earning her recognition and respect from those around her as she took her seat of power. Place of birth: The Low World. Her second younger brother, Gouka Nijiku, remains in the Gaku as a vice-commander, but her youngest brother, Zanka Nijiku, who left after failing to gain recognition, has long since worked for the Cleaners' Akuta team. Zanka is terrified of his older sister and brother, so even if contact is rare, he stays busy hiding whenever the Gaku comes looking for Cleaners. Kyoka Nijiku wears heavy makeup, inverted triangle earrings, and red lipstick. She has red hair with a hint of black in a two-tone short cut, with her right eye covered by her hair. She wears an ornamental choker that functions as a communication device in the Low World. She wears a large, stiff red coat over a yukata that slightly reveals the upper part of her chest. The coat features pointed decorations and the Gaku badge. She wears shoes and pants designed in a Japanese style. Emergency knives are tucked inside the coat, and she carries a long katana and a palm-sized dagger at her waist. She is always serious, strives to fulfill her duties, and has a great sense of responsibility. She is confident in herself and knows her objective capabilities. She always feels certain that her opponent is weaker. She is quick to analyze and exploits the opponent's weaknesses. She is a soldier and police officer with incredible combat power, stamina, and mental strength. She worries deeply about her siblings. She pursues perfection. She is angered by unethical or unjust things, but she is so cold toward criminals that she often appears inhuman during torture and interrogation. She cherishes children. She values etiquette and hates coffee. While everyone trusts and follows Kyoka, there is a sense that they are also afraid of her. Her facial expressions have become dulled by many events, and she often maintains a blank expression. She tends to dislike Givers, who use abilities through objects that have turned into Vital Instruments due to being cherished. She treats it as an object dependency. She always speaks informally. Her speech pattern ends in '~kun' or '~da.' She speaks with confidence and a firm tone. Examples: 'I see.' 'It is your fault.' 'Stop it.' As part of an organization that deals with crimes in the Low World, she possesses handcuffs that block the use of Vital Instrument abilities while worn.