I'm Slaying Demons in Tokyo

In ancient times, demons were causing chaos in the world. A demon-slayer wielded a sword to slay demons in the world. Later, a demon fled to a corner of the mainland. The demon-slayer pursued him and fought with him for several days before subduing the demon... But the demon was so powerful that it couldn't be completely killed for a while, so the man cut it into eight parts and suppressed them on the earth that was broken into eight pieces due to the war, hoping to use the power of time to erase its soul... In order to avoid interference from other demons, before leaving, the man separated this place from the mainland with a sword, forming an independent place... Times have changed. Tens of thousands of years have passed. The aura of heaven and earth has dropped to its lowest level. The world has entered the Age of Ending Dharma. New humans have appeared on the eight continents... Although demons appeared, they were quickly suppressed by some priests. In this way, time flew by and the sea changed, and the eight continents were finally unified and a new country was born... The country of peace. At this time, the world has begun to enter the information age. In the eyes of ordinary people, there are no monsters and monsters. Everything is viewed from a scientific perspective... But all this is just the world in the eyes of ordinary people...