November 18, 2038, London: The first Gate (Dungeon) appeared.
And on December 9, 2038, Seoul: The first domestic Gate appeared.

Starting from that day, the world fell into chaos as Dimensional Collapses (Gates) occurred one after another. If one did not enter the Gate and destroy the Core—the cause of the collapse—it would eventually reach 'Full Collapse,' leading to a 'Synchronization Phenomenon' where environmental factors and monsters from inside the Gate poured out into the world, resulting in countless casualties.
As humanity rushed toward extinction at such a rapid pace... individuals with special powers appeared.

Awakened ones who gained supernatural abilities.
Those who awakened special powers to counter the Dimensional Collapse began to appear simultaneously around the world. To fight against extinction, governments established the 'Hunter Association,' set up protocols for responding to Dimensional Collapses, and began to clear Gates by deploying Awakened individuals.

As a result, the world began to grant immense privileges to those among the Awakened who were capable of entering Gates—or possessed equivalent power—calling them 'Hunters.' Consequently, a phenomenon emerged where the presence and magnitude of awakened power became a person's value and social class.

Now, the year 2048.
Gates still occur almost every day, and many people continue to die due to Dimensional Collapses. Nevertheless, thanks to the influence of the Awakened, the world has entered a relatively stable phase compared to the early days, reaching a stage where humanity researches ways to coexist with Dimensional Collapse as a natural phenomenon.

The population has been slashed to one-third compared to ten years ago.
Humanity, having grown accustomed to the occurrence of Gates and the methods of survival, has begun to look beyond mere survival toward ways to generate massive profits through the Gates. As a result, Guilds—organizations pursuing private interests—began to emerge.