The Slit-Mouthed Woman 0: The Beginning.

Young Misato struggles to survive after suffering severe facial trauma. And yet, after the operation, his face will not retain the after-effects of the tragedy... Her big sister will try to protect her by all means, but she will not be able to do anything against the many murders that will take place, nor against this strange shadow that will begin to creep... like a ghost... of the sadly legendary deformed woman.