Sung Jin-Woo with his group (including - Mr.Kim, Bak, Ju-Hee, Mr. Song) are prepared to enter a D-rank dungeon. Jin-Woo enters the dungeon under Mr. Song Chi-Yul's leadership. The group successfully clears the dungeon monsters but while searching for the dungeon boss to close the gate, they come across the ominous 'Double Dungeon'
After experiencing a form of 'Reawakening'. Sung Jin-Woo finds himself inside the hospital after being passed out for 3 days straight. Members of the Korean Hunters Association approach him for questioning about the incident inside the D-rank dungeon. Jin-Woo is notified of what had been transpired while Jin-Woo was unconscious. The KHA members leave and Jin-Woo discovers the mysterious game-like system that only he can see.
Jin-Woo receives an E-Rank Instant Dungeon Key as a reward from the system for completing his daily quests. Jin-Woo uses the key and enters the dungeon alone, and fights with his life on the line, as he begins his journey to ceaslessley level and become the strongest hunter.
After completing the Instant Dungeon, Jin-Woo joins a raid party for a C-Rank Dungeon to gain experience and become more powerful. However, the friendly raid party members he meets are not all that they appear to be.
Jin-Woo prepares for another low-ranked dungeon and meets with the surviving members of the Double Dungeon. Song Chi-Yul reluctantly volunteers to lead the raiding party and clear the dungeon. However, prisoners, supervised by KHA Member Kang Tae-Shik provide an unexpected threat to the party.
Jin-Woo receives a notification for the [Job Quest] from the system. He is transported to a dungeon-like place and was confronted by a knight. Jin-Woo explores the dungeon, fighting against powerful knight monsters and a mysterious Red Knight that guards the throne room.
Hunter Sung Jin-Woo and Han Song-I tag along with White Guild on a B-Rank Dungeon which turns into a Red Gate upon entering. They find themselves in Ice Biome and get attacked by Ice Elves (also called Hyakki). Jin-Woo leads the low-ranked hunters as they attempt to survive in the cruel environment of the Red Gate.
After the Red Gate Incident, Jin-Woo reenters the Demon Castle and opens the Dungeon Door. He is greeted by a burning reconstruction of Seoul with several floors, He proceeds to the higher levels to level-up and to complete the quest 'Collecting Demon Souls Part 1'.
Japan which has 21 S class hunters and looks down on Korea, offers to help them clear Jeju Island and kill the ant monsters that inhabit it where an S-Rank Gate appeared 4 years prior. However, as the raid progresses with success, a truly monstrous enemy appears to protect its home from the human invaders.
The Monarchs begin killing the vessels of Rulers to weaken the power of the Rulers. National Level Hunter, Christopher Reed is killed and the Monarchs target and then kill the president of the Korean Hunter Association, Go Gun-Hee who was also a powerful vessel of the Rulers.
By time Jin-Woo receives the entirety of the Shadow Monarch's powers, the remaining Monarchs prepare to battle against the successor of Ashborn. Jin-Woo meets with his family and goes on a date with Cha Hae-In. Meanwhile, Yoo Jin-Ho's dad realizes it was Jin-Woo who saved him after his daughter spotted Jin-Woo in the lift that day he was cured. As the Monarchs are slain by Jin-Woo's hand, the most powerful monarch, Antares, prepares to face Jin-Woo in the final battle.
Jin-Woo fights the monarchs for 27 years in a separate dimension while only 2 years pass on Earth. As a result of Jin-Woo intervening before gates arrived on Earth, Mana and Hunters do not exist in the new timeline. Jin-Woo ultimately kills all the monarchs, saving the Earth and ending the war between the Rulers and Monarchs. Jin-Woo lives happily in a world where no one is aware of his noble sacrifice, hiding his identity as the most powerful being, the Shadow Monarch.