One day, the bright red sun ceased to shine, triggering the "Breakdown Phenomenon"—the destruction of Arata Kasuga's town and the disappearance of its inhabitants. Yet, all is not lost; by using the magical grimoire given to him by his childhood friend and cousin, Hijiri Kasuga, Arata's world is artificially reconstructed. To investigate the phenomenon, Lilith Asami appears before Arata as his artificial world suddenly disintegrates. He is presented with two choices: surrender the book, or die. However, Arata selects a third option—enrolling in the top-secret magic school Royal Biblia Academy, where six other magical users await him. Alongside Lilith, these six form the Trinity Seven, the school's elite who each enhance their own power and skill. Driven by the ambition to save Hijiri and aided by his newfound friends, Arata stops at nothing to prevent the destruction of his beloved hometown and to bring his best friend back.