Smart Nano

A young man who has been sleeping for three hundred years wakes up in this world, only to find that the world has undergone drastic changes. Giant beasts are everywhere, but humans can only hide between hundreds of meters high walls. However, the enemy from back then is still alive. In order to find out the truth, he embarks on a fight with the giant beasts, wandering in the towering jungle, just to gain enough strength to take revenge. But there is someone else behind the scenes. Who could he be?