In the otherworldly realm of Eima Tias, the battle between the Demon King and the Saintess ended with the Demon King being sealed away. His minions plotted to resurrect him, but their scheme backfired, shattering the Innocent Pieces of the seal. The fragments of the Innocent Pieces, along with the Demon King’s followers, crossed through time and space into the modern era. Now in the present day, the Demon King’s minions have begun harvesting energy from humans using monsters to achieve his revival.

In a world without the Saintess, there should have been no one to oppose the Demon King’s forces... yet Celestia, the Saintess from the other world, shared her power with modern-day maidens.

Clutching the Innocent Pieces infused with the Saintess’s power, the girls became shrouded in light. When the light faded, they stood clad in otherworldly garments, ready to protect humanity. What awaits them at the end of their battle against the monsters — victory, or the onslaught of tentacles?

[Translated from the official site]