Six years ago, in 2035—the skies all over the world split open without any warning.

Spatial rifts of unknown origin, "Gates," occurred simultaneously across the globe. Today, we call that day "Gate Opening Day." Inside the Gates existed monsters from fantasy that defied human common sense, and if left alone, a "Break" phenomenon would occur where monsters poured out into reality.

In that chaos, awakenings occurred in some humans. These awakened individuals, who gained physical abilities beyond limits or the power to handle mana, were called "Hunters," and humanity finally had a means to oppose the Gates.

Each nation legalized the Hunter system and established dedicated agencies. South Korea also established a system for awakened registration, rank screening, and Gate management centered around the Korea Hunter Management Association, building a conquest system in cooperation with private guilds.

Today, six years after the appearance of the Gates—2041.

Now, people accept this as a part of daily life. News and billboards display Gate status and Hunter rankings, and top rankers hold great influence. However, the moment a high-risk Gate or Break occurs, the entire city is still gripped by tension.

Gates open somewhere again today, and Hunters enter them once more.