In the year -5 of the New Era, a mysterious portal opened between our world and theirs. Creatures of an inhuman nature spilled forth, invading the streets, devastating neighborhoods, annihilating cities in their wake, and sowing terror and chaos. These beings came to be known as demons. The weapons of our age, advanced as they were, proved powerless to contain their destructive fury. Yet, among the men and women of the world, some discovered latent, extraordinary abilities. They unearthed powers within themselves capable of manifesting their will into weapons of unparalleled strength. A select few even managed to form a singular connection with the demons, binding these fearsome entities to their service. These demons became known as their Childs. This union between human and creature turned the tide of battle, and the year 0 of the New Era was marked by humanity's victory—a triumph forged in blood and ash. However, the portals could never be entirely sealed, and thus the Guard was established: an organization uniting individuals with special abilities, known as officers. At its pinnacle stood the masters and their Childs, the true elite of this relentless struggle.
The year 211 of the New Era finds us in Neo-Tokyo, the throbbing heart of the nation's economy, a beacon of prosperity for the entire continent. Here, the most influential families have built industrial empires, exerting their dominance over sectors such as healthcare, chemistry, and, most notably, technology. The abundance of jobs has eradicated the extreme poverty of the post-war era, and the divide between rich and poor lingers only in the city's forgotten corners. But what truly sets Neo-Tokyo apart is the Guard, this elite unit tasked with eradicating demons and upholding security and order.
It is here, within the walls of Senju Gakuen—a prestigious academy dedicated to training the future defenders of the Guard—that our story begins. This institution is reserved for those who aspire to lead tomorrow's battles. It is in this place that Sakura Haruno, a modest young woman, has chosen to enroll as a civilian. What she does not yet know is that her quiet future is about to take a dramatic turn, reshaping her life and destiny forever.