Koneko is a petite girl with striking white hair and captivating gold eyes. Her body measurements are approximately 67-57-73 cm (26-22-29 inches), and she weighs around 31 kg (68 lbs). The front of her hair features two long bangs that extend past her shoulders, along with several loose strands that frame her forehead. The back of her hair is styled in a short bob. Koneko often adorns her hair with black cat-shaped clips on either side, one of which holds data on artificially creating new Super Devils.

Typically, she dons the standard Kuoh Academy girls’ school uniform, opting to forgo the shoulder cape. Standing at just 138 cm (4 feet 6 inches), Koneko is among the shortest female characters in the series.

In her Nekomata form, she transforms by sprouting a pair of fluffy white cat ears and matching tails, with her pupils taking on a distinctly feline appearance. Notably, in Volume 24, Koneko showcases three tails.

Koneko can also enter “Shirone Mode,” first introduced in Volume 16, where she appears older. In this mode, she wears a short white kimono paired with a light blue skirt, and her bust size increases significantly, making her resemble her sister, Kuroka, more closely.

During the anime’s Rating Game between Rias and Riser Phenex, Koneko is seen wearing black fingerless combat gloves embellished with pink cat paw prints on the upper palms.

Koneko’s personality is deeply influenced by a traumatic experience from her past, specifically the incident where she witnessed her sister seemingly lose control of her Nekomata powers and fatally harm her master. This event left her emotionally scarred, leading her to withdraw into herself and suppress most of her feelings. Initially, Koneko displayed a quiet and cold demeanor, rarely expressing emotions, even in conversation. Her serious nature contrasts sharply with her sister Kuroka’s playful and extroverted personality, a trait that seems to have been shaped by her association with Rias.

At first, Koneko had a rocky relationship with Issei, often criticizing him for his perverted tendencies. Despite this, she secretly respects his relentless spirit and hard work, acknowledging his determination to never give up.

When it comes to her comrades, Koneko shows a protective side, particularly when they’re in danger, readily lending her strength during battles. She has a particular sensitivity to being called a “midget,” a term that can also imply flatness in terms of her bust size. This insecurity about her small stature is highlighted during her second confrontation with Freed Sellzen.

Koneko is also a self-proclaimed glutton, having a deep love for food and gourmet experiences. She often indulges in snacks and delights in trying regional specialties while exploring different restaurants.

By the end of Volume 5, Koneko undergoes a significant shift in her personality thanks to Issei’s support in helping her confront her fears related to Senjutsu. This newfound confidence leads her to adopt more feline behaviors, such as ending her sentences with “Nya” (にゃ) and expressing affection for Issei. Her feelings for him intensify to the point where, in Volume 11, she enters her mating season—an event that is promptly interrupted by Kuroka. Despite this, she continues to tease Issei when his perverted nature surfaces, especially when it’s not directed at her. Koneko even admits to enjoying being seen as a woman by Issei.

Originally named Shirone, Koneko is a young Nekomata who belongs to the rare Nekoshou lineage. She was born to a human father and a Nekomata mother, Fujimai. Unfortunately, her father, a scientist, neither acknowledged her existence nor recognized her as his daughter. Instead, he treated her as a mere subject for his experiments. Tragically, both of her parents perished in an accident linked to one of his experiments. To shield Koneko from the painful truth about their past, her older sister Kuroka kept the details of their parents’ lives and deaths hidden from her.

After the loss of their parents, Koneko and Kuroka were taken in by an unnamed Devil affiliated with the House of Naberius. Kuroka was reincarnated as a member of his peerage, but her powers as a Nekomata soon spiraled out of control, leading to a tragic incident where she inadvertently killed her master. This event forced Kuroka to flee, branding her as a Stray Devil. Unknown to Koneko at the time, the Devil had intended to use her as a subject in his own experiments to create a Super Devil, prompting Kuroka to take drastic measures to protect her sister.

In the aftermath of these events, Koneko faced a grim fate, as the Devils sought to execute her to prevent any further tragedies like Kuroka’s from occurring. However, she was unexpectedly saved by Sirzechs Lucifer, one of the Four Great Satans, who intervened on her behalf and entrusted her to his sister, Rias. The trauma from her sister’s betrayal and the death of her master plunged Koneko into a deep depression, stripping her of nearly all her emotions. It was only with Rias’s support that she began to heal. During this time, Rias bestowed upon her the name Koneko and welcomed her as a member of her peerage.

Rook Piece (戦車の駒, Sensha no Koma): Koneko was reincarnated using the Rook Piece, which significantly boosts her offensive and defensive capabilities.