There's a Little Liar from the Night Watch Department

A little liar who set up a stall to tell fortunes at a night market in an urban village was involved in a strange murder case on the night his master disappeared. He solved the case using the "magic skill of seeing people" and a logical chain developed through the tricks of the market. He was then recruited as a temporary worker by the "Night Watch Division" in the dark side of the city, investigating monster cases and shabby cases. The little liar grew into a "big hidden" who took on the life of an entire city.