Rinne, a high school girl born into a family of exorcists, carries a peculiar affliction: she cannot see the faces of other people. On her first solo mission, she and her companion, the storm goddess Yakumo, encounter an unusual monster unlike any they have faced before. This creature possesses a strange black crystal that allows it to revive itself endlessly, placing Rinne in mortal danger. She is saved at the last moment by a mysterious red-haired man named Jugemu, who possesses the power to permanently destroy these creatures.

Rinne soon discovers that her world is just one of many known as Strike Worlds, and that all of them are under a grave threat. A group of beings called Astrophages, including a masked individual known as the World Thief, are stealing the Master Orbs that sustain each world, causing them to collapse into nothingness. Jugemu, along with his ally Neo, a special forces member of the global defense organization Easter, is on a mission to stop them. To save her own reality from disappearing, Rinne decides to join Jugemu on his journey across dying worlds to recover her world's stolen Master Orb.

As Rinne travels with Jugemu and Yakumo, she forges new bonds with other warriors. In a collapsing world, she meets Masamune, a guardian swords-woman who protects her fading realm. They later ally with the strategic genius Kirinji and his revolutionary army against the monster hordes. Throughout these battles, Yakumo begins to uncover Rinne's deepest hidden secret, a mystery tied to her inability to see faces and a slumbering power within her soul.

The group eventually confronts the masked Astrophage, who breaches the barrier of the White Library to steal the Primal Orb, a relic even more ancient and powerful than the Master Orbs. During the battle on Strike Island, Jugemu is seemingly destroyed by a young Astrophage named Nowhere. Witnessing his death triggers a profound awakening in Rinne. She unleashes a powerful projectile of light from her spirit, reclaims her world's Master Orb, and manifests her true, immense power. Nowhere transforms into a monstrous being, boasting that he ignores everything he deems unnecessary to see. In the final battle, Rinne opposes him not just with her awakened abilities, but with the power of the bonds she has formed with her friends across the many dying worlds.