Itoko hakusho: Uzuku inran netsu (2009)

A man discovers that a hostess he fell in love with at first sight is in debt, so he takes her away from the snack bar. The two hide out in a house deep in the mountains to escape the yakuza who lent them money and their former colleagues, and their bodies are piled on top of each other out of love and lust. However, the woman have a other personality, which has been sleeping in the darkness of her mind, and now begins to awaken and gradually torments them both.