Kaio woke up naked in the middle of a forest, something unusual. Soon a small screen appeared before his eyes.

The Survivor's builder system.

Here was his chance to survive in this new world, building his own clothes, weapons, and hunting his own food. But to Kaio's surprise, he was not alone. There were people living in this place.

Men and women who dressed simply, pieces of skin covering their privates. "Cave men.

This was his adventure, to build in this new world to survive, to set up his own kingdom and form a harem of women. All while enduring the adversities of this world....