The year is 20XX. Isabella's homeland, Rosdank, has finally opened fire on its neighbor Irestia as relations soured under the King's direction. Four months into the war, Rosdank found itself at a slight disadvantage. Panicked, the King began deploying women and children to the front lines. Isabella was one of them. Though initially filled with confusion and terror, her combat skills ironically blossomed on the battlefield. She began to find pleasure in killing enemy soldiers and grew to love combat. As a berserker, she achieved massive feats, single-handedly annihilating an Irestia unit of 100 men and slaying renowned officers. Eventually, due to her beautiful, dance-like slaughter and the way her body became stained crimson as she overran the enemy, she became feared by Irestia as the "Blood-Stained Dancer." Thanks to Isabella's exploits, the tide of war shifted from a disadvantage to a stalemate. The one expected to break this deadlock for Irestia was Guest, who, like Isabella, had achieved unbelievable results on the battlefield. Hailed as the only hope capable of rivaling the "Blood-Stained Dancer," Guest was given the moniker "Blood-Stained Co-Star" in reference to her. Now, Isabella and Guest face each other on the battlefield, and the dance of mutual slaughter between the "Dancer" and the "Co-Star" is about to begin.