約定之日

In the not-too-distant past, a black fog known as the Crystalline Tide swamped the continent. Monsters known as Scourge Beasts roamed the lands. Humanity was forced to retreat to its own fortresses, waging a long and desperate resistance until the presence of a "Witch."
The Witch, a crystallized product of human alchemy, led humanity to victory. Under her leadership, the surviving humans, at great sacrifice, finally drove the Scourge Beasts to a remote corner of the continent. From then on, the Crystalline Tide finally dissipated, and humanity achieved a precious peace.
Now, the Tide has once again spread, and Scourge Beasts have reappeared. As the "Inspector," the fortress at the forefront of humanity's battle against the Scourge Beasts, you must work tirelessly with your witches to overcome this crisis and protect humanity's last hope.

—Welcome, Your Excellency, Inspector.