Another beautiful summer has passed for Illyasviel von Einzbern. She enjoys her time off from her magical girl duties after collecting the Class Cards with her closest friend Miyu Edelfelt. Her vacation is cut short when she and Miyu are kidnapped by Rin Toosaka and Luviagelita Edelfelt while out with her pals. Clock Tower notifies the magical girls that the out-of-control mana assumed to have been sealed is still propagating across Fuyuki City, implying that their task is far from done. Illya and Miyu are entrusted with resolving the anomaly after traveling to the source of the out-of-control mana. However, after casting their spell, Illyasviel realizes that she has been divided in two.