Fabio Zaccheroni serves as a prefect among the mage students at the College, a role granting him responsibility and authority to enforce rules and maintain order. Hailing from a respected magical family, he bears the weight of its expectations, reflected in his serious demeanor and strict adherence to regulations. He initially regards Chise Hatori with skepticism and rigid disapproval, perceiving her rule-breaking tendencies and connections to powerful non-human entities as dangerous disruptions threatening the College's safety and reputation.

His interactions are formal and protocol-driven, frequently reminding others, especially Chise, of College rules and their consequences. Over time, witnessing Chise's genuine struggles firsthand prompts a shift. While his core commitment to rules and order remains firm, he develops a grudging respect for her resilience and unique situation. This leads to a moderated stance: moving from overt hostility to offering measured assistance or advice within his role's boundaries, engaging in cautious, duty-bound cooperation when necessary.

Fabio embodies the College's structured, traditional magical world. His development centers on this pragmatic transition towards Chise—from rigid opposition to a rule-enforcing neutrality that acknowledges her presence while prioritizing his prefect duties and the institution's stability. His personal background beyond his family's status and College role remains unexplored.