The Sister of Yui {Diabolik Lovers x Reader}

Let's go back to the past where Yui was alone. She always wanted a sister that she can be happy, play with, and have fun. But after she realized her father loved her more thatn her she started to get furious, mad, angry (I know that's all the same) at her. But one day they got sent to a mansion and here is where the story began.....