"The Medicine Seller" is a mysterious, ruthless master of secret techniques. He travels all over Japan in the feudal era and hunts down evil spirits called "mononokes".However, when he discovers an evil spirit, he cannot immediately eliminate it; he must first understand its "form", "truth" and "reason" before he can use the powerful exorcist sword to confront the evil spirit head-on. Every ritual of his exorcism begins with a deep spiritual analysis and meticulous investigation.This process is extremely dangerous - before he can master the method of winning, he must face the evil spirits, deal with them, understand them, and uncover their past and motivations.In this battle between intelligence and will, if there is a slight mistake, the mind may be swallowed or even lost. He is not just a warrior who kills demons and eliminates demons, but also a traveler who shuttles between human nature and the underworld, looking for the truth in the darkness and revealing the secrets deep in the soul in fear.