The country of Eostia is considered a marvelous place. It is home to the five races: human, elf, dwarf, beast-kin, and demon. The land was once owned by the elves, but was gifted to the humans many centuries ago. The High Elves had granted the land to the human's greatest warrior and leadership family, the Arcturus'.

During that time the country had peace, but only relatively. For the demon races loved causing mayhem and misery. Orcs, imps, goblins, and many other demon races took pleasure in pillaging and raping, especially the latter. They would mow down crops and slaughter livestock. They would either kill men and children or enslave them for fun. And the women . . . were used as the demon's play things. They would be constantly raped to the point that the women would come to desire their tormentors or just simply have their minds broken.

One day all that came to a head when a huge fortress sprouted up in the north over a single night. "The Black Fort" as it would be known sucked the very life out of its very surroundings. The earth became black and barren, the water became as toxic as swamps, and even the air was not spared for it became so cloudy and red that it was nearly impossible to discern night and day. All of this energy was collected by the fortress and fed to the demons to give them strength, but also to keep them under control by their leader, the Queen of the Dark Elves, Olga Discordia.

For centuries this "Queen of Darkness" had used this army of demons to attack the human lands. And she would have succeeded in wiping them out if not for the High Elf, Celestine Lucross. Celestine was said to be the goddess reborn and led the humans and other races against Olga and the demons. For centuries these two elves fought against each other with each never truly gaining the upper hand in the war and always ending in a stalemate.

Over the years, Celestine had built seven City-Fortresses to defend against the north and she had recruited six individuals to help her defend these last resorts. Leader of the Knights and Celestine's right hand woman Claudia Levantine, leader of the dwarves Luu-Luu, Kaguya the Shrine Maiden, leader of the mercenaries Maia, and Princess Knights Alicia Arcturus and Prim Fiorire. These individuals would become to be known as Princess Knights of the Seven Shield Alliance.

Of course it was not just the Princess Knights fighting. Many mercenaries were hired out to help bolster the army's numbers. Over time it became commonplace to have mercenaries fight alongside soldiers and knights. One group especially had made an insurmountable impact, the Black Dogs or Kuroinu group. Led by their mighty leader Vault, the Kuroinu had pushed back the demons so far it opened up a chance to attack the Black Fortress. After so many years the war seemed to be coming to an end, thanks to the aid of the Kuroinu mercenary company. They just needed to make one more push.