The Story of Otherworld’s Conquest

A world-changing event occurred one day.
A massive earthquake shook the entire world, causing otherworldly creatures to emerge. The creatures razed the buildings, trampled the fields, and devoured the people.
It was the start of a disaster.

People later began to refer to these creatures as monsters.

Golden-scaled dragons, which should have remained a fantasy, and giants that could easily reach 30 meters in height, had become a reality. To deal with them, the countries have taken a variety of measures.

A handful of people saved people from the disaster at one point.

These people, later dubbed heroes in Japan, brought peace to the world by exterminating the monsters spreading across the globe.

In that world, five years later.

In Japan, the number of monsters prowling around had decreased, but "otherworld" dungeons remained.

A fantastical place that could bestow wealth, wisdom, possessions, and fame.

On the other hand, it was a nightmare environment in which losers were stripped of everything, including their lives.

A mediocre, unemployed man who survived the disaster picked up a sword and went to one of these dungeons. He set out to make a living as an explorer of otherworldly dungeons in the place where dreams and nightmares collide.

The adventures of a dungeon explorer begin.