Neko is portrayed as a striking young woman with long, pale pink hair that extends past her knees, often worn loose and slightly unkempt. She possesses heterochromatic eyes, with her right iris blue and her left green, a condition attributed to the Kagutsu Crater. Her figure is slender yet curvaceous, and her body measurements are listed as B89/W57/H88.

Her accessories include two distinctive golden bells, one worn as an earring on her left ear and another attached to a red collar around her right ankle along with a plain red collar around her neck. Initially, Neko avoids wearing clothing, but she later adopts a fuzzy, long-sleeved, short pale yellow dress, adorned with a large yellow bow layered beneath a red ribbon and bright yellow pom-poms. Matching boots in the same material and color scheme complete the outfit.

Following the Ashinaka Island Incident, her attire changes to a short, strapless pale pink dress decorated with darker lace and tied with a red wrap below the chest. She pairs this with white thigh-high socks patterned with designs, dark pink shoes, and a pink fuzzy jacket with white trim. During this period, she is also seen carrying Shiro’s red parasol.

In her cat form, Neko has light pink fur, a small hot pink nose, and rounded eyes with two pronounced eyelashes on each side. The red choker and golden bell remain constant in this form. Additionally, when enrolled at Ashinaka High School, she wears the standard girls’ uniform, notably without socks.

Neko is portrayed as a carefree and playful individual who delights in games and lighthearted mischief. She often fails to recognize the dangers her actions may cause, interpreting them instead as helpful or entertaining. Despite her whimsical nature, she is also strong-willed and confident, taking pride in her ability to use her powers to aid others and defend against enemies.

Her most defining trait is her deep affection for Yashiro Isana. When the two first met, he was the only person who did not drive her away, which led her to declare herself as his cat and claim that “Shiro belongs to her.” She is fiercely protective of him, going so far as to shield him from Kuroh Yatogami’s attacks and withhold the truth about his identity out of fear that he would leave her. Her devotion is also shown through moments of vulnerability: she blushes when Shiro embraces her, accepts without hesitation when he asks her to become his first clansman, and later breaks down in grief when she believes he has died, expressing a desperate desire to return his parasol.

At the same time, Neko’s personality has a childish and sometimes selfish streak, often clashing with Kuroh’s strict and serious outlook. Her immaturity, however, masks a deeper sense of insecurity and fear of abandonment. This is most evident in her manipulation of Yashiro’s memories, creating a false past that bound him to her. While she justified this by insisting that finding Shiro made him “hers,” her reluctance to restore his true memories reflects her underlying fear of losing him. This insecurity stems not only from her reliance on her powers but also from her past experiences, which left her aware of the dangers her abilities could cause and deeply anxious about being left alone.

As a child, Neko experienced the Kagutsu Crater tragedy, an event that claimed countless lives, including those of her parents. Only two years old at the time, she witnessed the catastrophic red light of the disaster, which she innocently described as “glitter.” Her parents shielded her from the destruction, ensuring her survival but leaving her traumatized and without memories of her past.

Following the tragedy, Neko wandered lost and confused until she was taken in by a couple who had lost their own son in the incident. Unbeknownst to her, her powers as a Strain caused the couple to believe she was their daughter, rewriting their memories. This ability soon extended to those around her, as she unconsciously altered the perceptions of entire communities, often using the stories she read in books as the basis for her fabrications. However, her powers proved inconsistent while humans succumbed to her illusions, a cat belonging to a nearby old man remained unaffected. The man repeatedly called her by a name she did not recognize, which unsettled her and reinforced her fear of her own abilities.

At one point, Neko was confronted by members of the Gold Clan, who revealed to her that she had erased the couple’s memories of their real son and warned that she had broken the rules of the Strains. They offered to take her in either as a prisoner or a pupil. Terrified, Neko rejected both options and forcibly expelled them from her home by altering their memories. Upon lifting her own illusions, she uncovered the truth: the altar to the couple’s deceased son had always been there, concealed by her subconscious manipulation. When her adoptive parents returned and realized what had happened, they called her a monster and abandoned her.

Left alone and burdened by guilt, Neko recalled a book her adoptive father once read to her, I Am a Cat, which told of a proud and independent feline who could live freely. Inspired, she embraced a new identity, named herself Neko, and transformed into a cat, vowing to live apart from humans.

For a time, she lived as a stray on Ashinaka High School’s campus, surviving by stealing food and avoiding detection by both students and security robots. She became an unnoticed observer of daily life, even attending events such as the school’s production night.

Eventually, her solitary existence changed when a young man later revealed to be Adolf K. Weismann fell through the school gymnasium roof and landed unharmed. Initially defensive, Neko quickly warmed to him, allowing him to pet her and forming an immediate attachment. Discovering he had no memory of his identity, she used her powers to implant a new name for him: Yashiro Isana, marking the beginning of their bond and her central role in his life.

As both a Strain and a member of the Silver Clan, Neko possesses a diverse range of abilities that make her one of the most enigmatic characters in K. Her powers are primarily centered around illusions, sensory manipulation, and memory alteration, though she also benefits from the unique properties of the Silver Clan.

Silver Aura
As a Silver Clansman, Neko wields the clan’s distinctive silver aura, which grants the ability to manipulate gravity.

Sense and Perception Manipulation
Neko’s primary Strain ability allows her to alter the senses of humans around her at will. She can influence emotions, implant visions, and project false perceptions onto her targets, effectively painting over their reality with illusions of her choosing. Her power, however, has limitations: illusions break when she moves out of range or when powerful individuals such as the Kings forcibly dispel them. Furthermore, her abilities are ineffective on individuals whose emotions she cannot understand or interpret.

Transformation
Neko can freely alter her physical form, most commonly shifting between her teenage girl form and a small pink kitten, retaining her powers in either state. Abrupt transformations are often accompanied by a brief puff of smoke.

Illusion Creation
She can project complex environmental illusions, ranging from subtle alterations of surroundings to complete fabrications of settings and people. These illusions can include fabricated individuals with distinct voices and movements, often incorporating cat-like motifs. Once cast, her illusions can persist for days, provided they are not disrupted.

Sensory Disruption
A fundamental aspect of her illusions is the ability to distort her victims’ five senses, particularly sight and touch. Those affected perceive the illusion as reality, unable to notice external stimuli such as weather until the illusion is broken.

Memory Manipulation
Neko can manipulate or implant memories within individuals or groups, even fabricating false identities or convincing large numbers of people that they share prior relationships with someone unfamiliar. She is also capable of restoring genuine but forgotten memories. However, this ability is bound by proximity: once she and her companions left Ashinaka, for instance, Kukuri Yukizome no longer remembered Yashiro Isana when he attempted to contact her, suggesting her influence was limited by distance.

The name “Neko” (ネコ) is the Japanese word for “cat”, directly reflecting her ability to transform into a feline and her decision to adopt the identity of a cat after the Kagutsu Crater incident. The simplicity of the name underscores her playful, childlike personality and her attempt to distance herself from the painful memories of her past.

The name Miyabi Ameno (雨乃 雅日, Ameno Miyabi), used by the Green King Nagare Hisui when addressing her, carries more formal connotations. Miyabi (雅日) can be translated as “elegance” or “refinement”, while Ameno (雨乃) literally means “of the rain”. Neko herself does not recognize this name, symbolizing her disconnection from her past identity and her rejection of the life tied to it.