Mia Connery operates as agent 009-7 within the Nine Number Group, an all-female cyborg spy unit serving the Western Bloc's Zero Zero Organization during a prolonged Cold War. Her cybernetic enhancements enable advanced disguise and infiltration capabilities through a specialized biological tissue composing her entire skeleton, muscles, and skin. This allows complete physical transformation into nearly any individual by direct manipulation of her bio-skin via cybernetic systems and willpower, replicating appearances, voices, and personalities with precision. A distinctive earring typically remains visible during transformations.

Her operational history includes missions against the Eastern Bloc, notably an early assignment to rescue Russian defector Zond Soyuz—possessor of a sought-after energy source—from captor Ivan Godunov. While agent Mylene Hoffman gathered intelligence on Soyuz's location, Mia infiltrated Godunov's inner circle using her shapeshifting abilities. Though the mission failed to extract Soyuz alive, Mia secured his invention and eliminated Godunov.

Personality-wise, Mia exhibits the most playful demeanor among her Nine Number Group colleagues, occasionally employing her transformations for pranks like impersonating a priest in the rectory above their meeting chambers. During operations, she maintains a cool, professional focus on objectives with minimal sentiment. She reports directly to group leader Number Zero.

Within team dynamics, her deep-cover specialization complements roles like Vanessa Ibert's (009-3, electronic analysis) and Berta Kastner's (009-4, heavy weaponry). The Nine Number Group functions as one of ten units under the Zero Zero Organization, advancing Western Bloc interests. Mia appears across all installments of the 2006 anime adaptation, including twelve broadcast episodes and the unaired thirteenth episode on the Japanese DVD release. Her role, abilities, and background remain consistent throughout the series and official media adaptations.