Anne Sieber, a prefect of the White Cats House at Dahlia Academy, sports long honey-blonde hair pulled into ponytails secured by a white frilled headband adorned with black bows. Her sapphire-blue eyes complement an average stature and curvaceous frame. The standard White Cats uniform she wears features a frilled blouse with a maroon bow, a tailored white buttoned coat, a flowing black skirt, calf-length frilly socks, polished black Mary Janes, and completes the look with a red prefect armband.

Commanding respect with her serious, diligent demeanor, Anne executes duties with unwavering professionalism, earning admiration for her precision. She champions merit over allegiance, as shown when praising Romio Inuzuka’s diligence despite his Black Dogs House affiliation, even offering him a meal in gratitude. Her competitive streak flares when she embraces challenges to surpass peers, yet she swiftly penalizes complacency—evidenced by stripping Romio of his helper duties following a lapse in commitment.

Her dynamic with Cait Sith balances stern admonishment of his crude antics with an undercurrent of mutual concern. Post-graduation, their bond deepens as she assumes the role of his nurse and cautiously returns his affections, though proposals of marriage fluster her into reserved silence. Paradoxically, Anne harbors a secret penchant for whimsical aesthetics: decorative sticker collections, an array of teddy bears, and bear-patterned undergarments fill her private world. She fiercely guards this vulnerability, as when she swiftly silences Romio after he glimpses her in an ursine costume.

During student elections, her authority shines as she quells dissent within her ranks to maintain decorum. Her dorm room serves as a teddy bear-filled sanctuary, and her surname nods to Siberian Cat lineage. Later iterations of her character design underwent refinements in the source material’s subsequent chapters.