Giulia is the ruling Commander of the Guardswomen in a post-apocalyptic world where environmental catastrophe wiped out the male population and pushed humanity toward extinction. She commands a faction focused solely on preserving humanity through the "ICE" project, which she deems the sole means of survival. This mission directly opposes the Kisaragi faction, which accepts humanity's demise.

She maintains strict control over subordinates, deploying a group of girls as test subjects for the ICE project and for fulfilling needs ranging from sexual services to chores. Giulia employs manipulation and coercion to achieve her goals, such as promising Aoi the chance for future pregnancy in exchange for betraying comrades.

Giulia's relentless pursuit of ICE—a nanotechnological life-creation substance—drives the central conflict. She orchestrates military operations to secure ICE specimens, viewing them as essential to overcome human infertility. Her methods authorize morally questionable experiments and deploy force against both the Kisaragi faction and emergent biological threats.

Her character embodies ruthless pragmatism, committing atrocities justified by her belief in humanity's preservation. This includes endangering followers and escalating hostilities, which directly fuels the catastrophic terraforming event initiated by Kisaragi. This event remakes Earth in a non-human-compatible image.

Giulia acts from the conviction that humanity's survival outweighs all ethical constraints. However, her actions inadvertently hasten the extinction she sought to prevent. Her role concludes amidst the devastation triggered by the terraforming process, underscoring the outcome of her ideological absolutism.