Awakening to find herself sprawled on a floor of hard steel, the first thing that greets Kohaku's eyes is a strange talking sword named ExeBreaker. Unsure of where she is or what's going on, she agrees to this sardonic sword's proposal to join forces, and together they journey deep into the heart of a transformed Cogen City—once Kohaku's home, now a collapsing ruin. Both mystery and mayhem await her, but with the power of ExeBreaker's Ouroboros System on her side, nothing will stop her from discovering the truth of what happened to her beloved home.