Song Jihyeon, has been away from her family for  4 years now. She was sent to US as an exchange student since she was in 9th grade. Coming back to Seoul to study college, she has to live with her Elder sister, Snsd's Seohyun. Her identity was unknown to the world. The people around her doesn't have any idea she's a sister of a kpop star, not even Snsd's member knew that Seohyun has a younger sister, Except for Yoona. She's childhood friends with the both of them. Upon her stay