On the night of a meteor rain, monster-filled dungeons started sprouting all over the world. Peaceful days have come to an end and it has become the duty of the people to dive into the dungeons and hunts monster. Having only the lowest rank ability, I was ridiculed and was turned into a luggage carrier. I spent diving in the dungeon. These hopeless days ended the time I picked up a piece of paper. This is a story of how I, who was the weakest become the strongest and saved these two worlds.