Yoona,Taecyeon and Yuri are childhood friends. Taecyeon and Yoona fall in love to each other and they just start to dating until one day Yoona knew that her sister, Yuri said that she likes Taecyeon since their childhood. Yoona didn't want her sister feels hurt. How about their relationship? What is gonna happen ? What will Yoona do ? What will gon