Anne is a young girl who endured experiments at the Berühren Corporation facility alongside Tetsuro Arahabaki. She possesses naturally red hair, red eyes, and distinctive cut scars on her nose and right cheek. Her existence centers entirely on her sister Ende, whom she fiercely protects and cares for. Anne accepts her role as a tool for Berühren solely because it allows the sisters to remain together, believing they have no other path to safety.

Deployed by Berühren to attack children and lure Tetsuro, Anne and Ende face pursuit by Kyusei Group assassins. Tetsuro, controlling Juzo Inui's body, aids them. Anne rejects his offer of escape, insisting Berühren is their only home. She commands Ende to transform into her spider-like Extended form and attack, resulting in Tetsuro being paralyzed by Ende's poison-tipped projectiles. When Ende loses control during the rampage, Anne calms her by holding her hand—a vital method established in the facility to soothe Ende's transformation-induced panic through Anne's physical contact.

Later, Hugh Cunningham of Berühren orders further attacks. After failing to capture Tetsuro, Cunningham declares Anne and Ende expendable, commanding their elimination. Tetsuro intervenes to protect them, revealing Juzo's identity. Cunningham forces Anne to command Ende to fight again. Ende momentarily resists, reaching out for Anne's hand instead of attacking, but Cunningham injects Ende with a drug causing complete loss of control. In the ensuing chaos, Ende's uncontrolled attack blasts both Tetsuro and Anne. Fatally injured, Anne uses her dying words to blame herself for forcing Ende into the conflict and begs Tetsuro to save her sister.

Anne dies shortly after from her injuries. Following Anne's death, Mary Steinberg rescues Ende, removing her dangerous spider-like modifications and replacing them with safer, humanoid prosthetics, enabling Ende to live normally. Anne possesses no explicit combat abilities or extensions; her role is strategic and emotional, focused on managing Ende's transformations. An orphan and test subject at Berühren, her entire motivation revolves around protecting Ende at any cost.