The war between humans and demons that took place thousands of years ago resulted in heavy losses. The humans and demons were divided into two spaces, each recuperating and recuperating. Nowadays, the human world is developing rapidly and various technologies are constantly evolving. Most people are not aware of the existence of the demon world. Only a few people are aware of it and are on guard against it. Nowadays, humans have invented many games, and people exercise themselves in the games. The demon world has almost rested and is planning the next invasion. What method will they take this time...