K2, known as Katy, is a feminized clone engineered from Kei via chromosome manipulation by the organization Fraud. As a Headmeter, she wields psychic abilities rivaling Mr. J’s potency and commands pursuit units hunting Kei and Ai. Her intense narcissism ignites fervent romantic fixation on her genetic source, Kei, breeding hostility toward Ai—viewed as monopolizing Kei’s affection. She relentlessly schemes to eliminate Ai, craving Kei’s undivided devotion.

During a pursuit operation, physical contact with a topology wall induces catastrophic memory loss and psychological regression, reducing K2 to an infantile mental state. In this fragile condition, she forms a deep attachment to Reiden Yoshioka, the policeman who rescues her.

Subsequent memory restoration fails to reverse her allegiance. Despite fully recalling her role in Fraud and prior obsession with Kei, K2 retains her bond with Reiden and discards her original mission objectives. Her operational history includes leading specialized units under Fraud’s hierarchy, deploying both psychic combat expertise and tactical command. The topology wall trauma fundamentally reshapes her motivations, converting her from antagonist to ally within Reiden’s group.

K2’s narrative arc culminates in this realignment, prioritizing her connection to Reiden over previous loyalties and obsessions.