After the appearance of portals known as "gates" connecting the world of monsters to humans, a small portion of the population has acquired superhuman powers to defend against the monsters. The protagonist of the story, Sung Jin-Midoriya, is a member of the lowest rank of hunters and is the weakest hunter in all of South Korea (everyone from mha is in Korea and so is U.A), barely stronger than a normal human. One day, he and some other hunters find themselves trapped in an extremely dangerous and rare "Double" dungeon, and only a few of them survive and manage to escape. Sung Jin-Midoriya himself "dies" but manages to complete all the trials in this dungeon. He then wakes up in a hospital and finds he has turned into a reawakened "player" who can now see an interface classed as the SYSTEM showing him quests, stats, inventory, store, and levels, along with the unique ability to grow exponentially stronger. Sung Jin-Midoriya begins on a quest to become the strongest hunter in the world and uncover the mystery of the world of monsters.