On an utterly ordinary day, a mighty force suddenly brought the world to a standstill. In a way no one could understand, it caused explanations to appear in everyone's mind, but before they could be finished---
Another mighty force suddenly enveloped the world. The two forces clashed, dividing the Earth between them along the Yangtze River region of China, with the boundary stretching all the way to the Southern Hemisphere.
During this time, everyone was dazed. But soon, everyone came to their senses. The two forces seemed to have reached an agreement and established a rule: everyone on Earth would be split into two groups. One group would enter a world of cultivation, and the other a tower-defense world.
In China, roughly speaking, those north of the Yangtze River would enter the cultivation world, while those south of it would enter the tower-defense world.
The protagonist was a soon-to-be university student who had just graduated from high school. By sheer chance, he happened to be right on the boundary between the two forces. Perhaps it was a bug, but somehow he could enter both the cultivation world and the tower-defense world.
And so, a grand epic began.
