This show is similar to Mushi-shi in many ways. Like Mushi-shi, it is structured as a collection of short stories, each with its own characters, settings, and ideas. A medicine seller travels the land in search of mononoke to defeat, which are demons born from human hate, regret, and sorrow---the darkest recesses of the human heart. Each storyline, which consists of either two or three episodes per story, play out like a detective story. The demon slayer must figure out three things before he can draw his sword and defeat each mononoke. He must know the Form, the Truth, and the Reason; that is, he must know its appearance, the truth of why it came to exist, and the reason it has a grudge against certain people.
This show delves into the deepest and darkest recesses of the human heart. Each demon is born because of some horrific injustice or evil action committed by people against others. It does not shy away from delving deeply into dark topics; it does not shy away from confronting the evil which resides in every heart. The story's narrative never takes away responsibility from the sinners, who either meet horrible ends or are forced to live on with their guilt (which is so refreshing in this age of blaming others for our own mistakes). I particularly like how sinful actions have consequences not just for the sinner, but for those around them as well, creating a never-ending cycle of perpetrators and victims. There are so many deep and profound messages in this show.
Note on the Style: The style is supposed to resemble kabuki and noh theatre, which often feature gaudy colors, crazy masks, and wild make-up with specific symbolism attached to each. I love the beautiful detail in the show.