All of this is thanks to the new materials brought by the planetary impact. Humanity survived once again, and afterward, they divided themselves into cities, each within a vast isolation wall, gradually restoring their ecosystems to allow for human survival and reproduction.,One day, a certain city released a video from several decades ago. Finally, humans understood why that explosion occurred, the one that changed all of humanity.,Brilliant City, a city built within massive defensive walls. It is called Brilliant City because it was the first human city to utilize planetary unique materials to develop an artificial sun. It is a gigantic city with a population exceeding 30 million.。