It was finally the day they got married, but suddenly, Yui had some doubts on herself about this marriage, does she really loves him or only sees him as a brother? Somehow, she felt sick for the past few days. What is she going to do? Where will she run to? Luckily there's another vampire helping her, and these vampires said that they were sent by Karl Heinz! This is a sequel of My Sweet Sister, Hope you like it.