The mischievous twins, Hikaru and Kaoru, suddenly find out that they have a long lost older sister who has been living in America. At first, they don't give her a chance and completely shut her out. Overtime, the twins start opening up to her, getting to know the kind of person she is, vise versa with her getting to know the kind of people they are. As time passes, their sister ends up developing feelings for one of the Host Club members. Later finding out, the twins help their big sister out the Hitachiin brothers way.
Haruhi and her older brother have been accepted into an elite private school for rich kids becasue of their scholarships. They are both exceptional children, haruhi struggles with her relationship with tamaki, mori, and hikaru. While her older brother yumi struggles with his band and ex boyfriend at the same time he struggles with his cute senpai honey and this cute but creepy guy Umehito Nekozawa aswell as club vice president, kyoya. both fujioka siblings struggle to find their way their first year at ohshc