Yui and her sister had to go to the sakamaki mansion. Something that shocked the brothers was that they were twins! (Y/n) didn't even look like her so called "twin". But there is a secret behind as to why (y/n) acts the way she does. She refuses to tell the brothers till one day the eventually find out. What is (y/n's) secret. And what is she really hiding from not only the vampires but from yui?