Shion Uzuki was assigned to Vector Industries' First R&D Division at the young age of 18 in T.C. 4763. Her official title is "Chief Engineer of the KOS-MOS Project General Operation System Research Center, Vector Industries First R&D Division". She has a bright, cheerful personality and is ever the optimist, perhaps to hide the scars of losing both her parents as a child and her fiancé two years ago. In Episode I, it was revealed that she suffers from astraphobia, the result of two traumatic incidents which happened during lightning storms; losing her parents and later her fiancé, Kevin. She does not get along well with her brother, Jin Uzuki, who is thirteen years her senior. Shion ends up being swept, along with KOS-MOS and her co-worker Allen Ridgeley, into a conspiracy concerning the very fate of mankind itself.