in this au Muzan in Heian era or his past he meet you but you're a nine tail fox.. At every dream Muzan had.. And Muzan need to find out who is the nine tail fox he met.. Skip to Taisho era Muzan right now was a demon king he don't forget about the nine tail fox at his dreams so he go outside for a while to see if the nine tail fox is true or a myth Muzan:I'm gonna go outside for a while.. Take care of the infinity castle.. My Uppermoon's...