Fog-Dispelling Gun

In the Eternal Mist World, I don't know when it was formed, and I don't know the specific size and location. Over the past fifty years, people have been appearing strangely, but no one has the previous memory. Since the first batch of people appeared, they have discovered that there are some technologies and buildings here. And in this world of eternal fog, there is a mysterious phenomenon. An endless circle centered on the first group of people appears every 10,000 meters away. There is no gap, a fantasy fog with no vision, and the distances vary. Fifty years later, the young siblings in the owner's mansion called "Flowers in the Mist" will embark on a journey to explore the mystery of the fog during a shopping trip.