Horizon Meister, Mainstream 1: New Order

On a parallel Earth, a population of individuals possessing extraordinary supernatural gifts, designated as "Meisters" or "Power-Users," dedicated themselves to safeguarding innocent civilians from a monstrous extraterrestrial menace known as the Nightbeast, a conflict that ultimately escalated into the devastating War of the Nightbeast, resulting in the obliteration of cities and countless casualties.

To ensure the safety of all individuals and prevent any harm, a newly established organization identified as the Interdimensional Administration Union, also known as IAU, enacted legislation titled "The Act of M." This act empowers individuals designated as Meisters to become part of a collective known as the Anti-NightBeast Defense Enforcement, with the ultimate goals of establishing peace and combating the threat of Nightbeasts.

In the bustling metropolis of New Arc City, Raika Narukami, a young girl, lived peacefully with her father until someone summoned her to enlist in the Anti-NightBeast Defense Enforcement