Mari is a shy and introverted young woman who finds herself way outside her comfort zone when she is chosen as a candidate for the mysterious role of Guardian. She is tasked to protect the realms from the threat of the Void and its monstrous offspring.

Bound to a Realmforge -a powerful structure that can manifest in various forms- Mari sets out to train the inhabitants of targeted realms into formidable warriors capable of combating the Void's relentless onslaught.

With the fate of her own Earth hanging in the balance, she must make difficult choices that will shape the fate of not only her reality but countless others.