The discovery of a black crystalline mineral known as Originium has accelerated technological advancement in the world of Terra, with its high energy yield allowing people to demonstrate abilities akin to magic called Arts. Large veins of Originium can naturally be found at the sites of Catastrophes, various forms of natural disasters caused by the mineral itself.

However, the usage of Originium comes at a price, as there is a high risk of getting infected with Oripathy—an incurable and highly contagious disease. Because nations subject the infected to harsh discrimination, the oppressed begin a dissident movement. Calling themselves Reunion, the rebel faction mercilessly destroys cities, further contributing to the already calamitous nature of Catastrophes.

Rhodes Island, committed to treating the infected and uninfected as equals, is a paramilitary pharmaceutical organization believed to be the most advanced in its research for the Oripathy cure. Unfortunately, the person spearheading the project—an enigmatic figure known only as the Doctor—suffers from amnesia, effectively impeding what might be the only hope for the infected to break free from their chains of despair.

Arknights: Reimei Zensou adapts the Hour of An Awakening main story arc of Hypergryph's 2019 mobile game Arknights. The anime supports 5.1ch surround audio and a 2.35:1 CinemaScope screen ratio to provide a movie-like watching experience.

The series was released in a Blu-ray box on February 22, 2023.