Mikan older sister

In this au mikan had a older sister which is aiko sakura 18 years old and the same age as imai subaro . Aiko sakura was born when her mother yukihira was 18 and her father wa 23 in this au and subaro ang aiko had the same class in class b when she was 5 years old in the past and her father death she also known who it is and known the secret of the academy in the young age . Aiko sakura alice is wish alice,stealing alice and nullification alice. What happened when mikan know that she had an older sister when her and her friends peak at past what well happened and what is the reason why whole academy don't remember her what happened to aiko sakura
Mikan was given an advice to her uncle which was the meddle school prencipal to watch the past by the teacher of special ability claa what will mikan find about the past what will she react to it and the secret about the academy and whole beggining of