Michiru Kita is a weak-spirited girl who has a hard time saying what’s on her mind. One day, she notices mysterious, ring-like markings around the necks of two of her classmates, Chika Akatsuki and Shito...

Rumors stir throughout the land: when the wielder of the black sword draws his dark blade, all who stand in its path are torn asunder. Köinzell, the mysterious young boy who carries the black sword, undeniably...