The Jiangcheng of Huaguo in parallel time and space looks like a prosperous city on the surface, but there are countless indescribable strange things hiding underground - human-faced rats in the sewers, peeping eyes in office buildings, and faceless passengers on midnight buses. These are all faint projections of the rulers of the past.
Human beings have established a secret organization "Secret Keepers Association" to cover up the truth to avoid panic while hunting out-of-control weirdos; there is also a cult organization "Abyss Chanters" in an attempt to summon the Old Ones to come and exchange for eternal life.
