The tensions stemming from the Selector battles appear to have dissipated, with the surviving participants swiftly moving past the entire ordeal. Yet, Kiyoi Mizushima senses that the conflict is far from over. Even after Kou Satomi's defeat, his supporters are already working behind the scenes to resurrect his schemes. Mizushima's suspicions are soon validated. The Selector battle system not only resurfaces, but a new mechanic is also introduced. Participants are issued a special key card that unlocks with gold coins, unleashing a concealed power. Recognizing the formidable adversaries ahead, Mizushima starts recruiting capable allies in her quest to finally shatter the cycle of darkness.