It's been over a decade since the sudden appearance of the "gates"—the paths that connect our world with a different dimension. Since then, certain humans have awakened to supernatural powers. We call these individuals "hunters." Hunters make their living by using their powers to conquer dungeons inside the gates. In this world of tough customers, the low-ranked hunter Jinwoo Sung is known as "the weakest hunter of all mankind." One day, Jinwoo gets fatally injured when he runs into high-rank double dungeons hidden within a low-rank dungeon. Just then, a mysterious quest window appears in front of him.

On the verge of death, Jinwoo decides to accept the quest and starts leveling up... while the others aren't.

[Source: Crunchyroll]