The modern urban background is calm on the surface, but in fact there is an undercurrent. The boundaries between Yin and Yang are blurred, and supernatural events occur frequently, but ordinary people cannot detect them. There is a type of "boundary keepers" who hide in the market. They may be Taoist priests, Feng Shui masters, retired strangers, or like the protagonist, they inherit the ancestral business and silently guard the order of the world.
