After the Selector battles seemingly fade into the past, Kiyoi Mizushima remains vigilant, sensing a lingering threat. Despite Kou Satomi's defeat, his followers clandestinely work to resurrect his malevolent plans. Mizushima's fears are soon validated as the Selector battle system resurfaces, now accompanied by a mysterious new feature. Participants are granted key cards requiring gold coins for activation, unleashing untold powers. With adversaries looming, Mizushima embarks on a quest to assemble a capable team, determined to shatter the cycle of darkness once and for all.