Following Akihito Kanbara's reunion with Mirai Kuriyama, whom he believed had vanished after defeating Beyond the Boundary, he learns a harsh truth: Mirai has lost all memory of him, their friends, and her time as a Spirit Warrior. Heartbroken yet understanding that this amnesia gives Mirai a chance at a normal life free from the supernatural world that once marginalized and exploited her, Akihito accepts the situation. Though intended for Mirai's well-being, the cost is steep; Akihito and their friends must conceal her true past, preventing them from being openly close to her.
Gradually, fragments of Mirai's past begin to resurface, and a new, mysterious threat emerges, drawing a horde of shadowy creatures to the city, intent on hunting her. As the danger grows, Akihito must fight fiercely to protect himself, his closest friends, and Mirai, the bespectacled girl who means so much to him.