After emperors of successive dynasties pass away, they are transported to a mysterious walled city, where one day is equivalent to one year in the mortal world. When the city gates open, they can enter a perilous otherworld and obtain precious dragon pearls by slaying monsters. Qin Shi Huang, Liu Bang, and other emperors set aside their dynastic grudges, unite and cooperate within the city, reclaim wasteland for farming, hone their abilities, and fight side by side against dangerous mythical beasts and trials of illusory realms, learning lessons about governing a nation and conducting themselves as people through their adventures and training.