Suzuko Homura and Chinatsu Morikawa's victory against the nefarious Bookmaker Kou Satomi has allowed the two girls to finally return to a life of normalcy and seize the chance to move on. However, the peace does not last long, as Kiyoi Mizushima requests Suzuko's help to prevent the next cycle of Selector battles; even after Satomi's defeat, efforts to continue his plans seem to persist. Troubled by lingering doubts and the unresolved situation, Suzuko decides to assist Mizushima with her investigation—unknowingly becoming involved in the escalating fight that will determine the fate of Selectors once and for all.