Neko appears mysteriously as a cat, frequently accompanying Yashiro Isana (Shiro) at school. She later reveals her ability to transform into a human girl, forming a close bond with Shiro and Kurou Yatogami. Her origins remain undefined, with no known past beyond her existence as a shapeshifting cat. She wields the power to manipulate perceptions and memories, using it to conceal locations, shield companions from danger, and evade threats targeting Shiro from various clans. This ability proves vital, even temporarily restoring Shiro's lost memories, though it fails to fully reveal his true identity as the Silver King. Throughout conflicts involving clans like Homra and Scepter 4, she consistently supports Shiro, leveraging her powers for protection and evasion. After Shiro vanishes following the battle on the school island, she dedicates herself to searching for him alongside Kurou. Her involvement deepens during incidents concerning Anna Kushina, the sole surviving female member of the Red Clan. She participates in Anna's rescue when targeted by the Green Clan, showing loyalty and cooperating with former adversaries for common goals. Despite her human form, she retains distinct cat-like behaviors: playful mannerisms, a preference for fish, and occasional jealousy. Her relationship with Shiro is central, defined by unwavering devotion, protectiveness, and viewing him as her primary anchor. After Shiro's return and the resolution of conflicts among the kings, she continues to stay with him and Kurou, maintaining their trio dynamic. Her character shows subtle development, moving from a primarily dependent figure to occasionally participating more actively in confrontations, while her core traits of loyalty, protectiveness, and attachment to Shiro remain constant.