The world was stunned when ten years ago, strange “Gates” suddenly began to open. From within them emerged dangerous monsters that neither bullets nor bombs could destroy. To fight them, some people suddenly gained superpowers, whom people now call “Hunters.” Sung Jin-Woo is also a hunter, but the poor fellow is so helpless that people mock him as “weakest hunter.”
One day, Jin-Woo and his team find a secret passage in the dungeons from an ordinary man. Lured by the treasure, they enter, but there they face a death beyond their imagination. Everyone died, but Jin-Woo came back from the jaws of death. When he opened his eyes, he saw a strange game screen in front of him, which only he could see. This “System” tempts him to become the most powerful, but it is not going to be so easy.
