It all began with the first 'Gate' that appeared in the United States.

An unidentified dimensional rift emerged in the heart of a city, and from within, 'Kaiju'—creatures humanity had never encountered before—made their appearance.

Kaiju from the early Gates were manageable enough to be suppressed with modern firearms and armored forces. Nations around the world perceived this as a new form of biological disaster and controlled the situation relatively easily by mobilizing their militaries.

However, that was only the beginning.

As time passed, the Gates grew larger, and the emerging Kaiju became incomparably more powerful. As if testing human response capabilities, the Kaiju evolved into entities with high intelligence, overwhelming physical prowess, and special supernatural abilities.

Subjugation became difficult with conventional weaponry as casualties mounted, and eventually, Gates began to appear simultaneously across the globe—from the US to Europe, Asia, Africa, and South America.

Human civilization faced the greatest threat of extinction in its history.

In this desperate situation, major nations set aside their political conflicts and established a joint research institution.

They launched humanity's final plan.

Artificial Ability Injection Project (AAIP)

This project aimed to artificially awaken supernatural powers in the human body using unknown energy extracted from Kaiju corpses and special substances found inside the Gates.

Most test subjects were special forces operatives and soldiers from various nations.

However, humans were not originally designed to handle such power. Numerous subjects lost their lives to physical collapse, mental contamination, and berserk states, resulting in an extremely low success rate.

Nevertheless, humanity had no luxury to mourn the failures.

Project leaders defined the sacrifices as an 'inevitable cost for human survival,' and after countless losses, superhumans capable of using their abilities stably finally began to emerge.

They were no longer mere soldiers.

They were reborn as living strategic weapons, created for the sole purpose of hunting Kaiju.