Park Yoon Hee(Jiyeon) and Lee Sung Jo(JB) were bestfriends since they were still young.Sung Jo has a secret crush on Yoon Hee..Yoon Hee was very modest and kind who is the opposite of her twin sister Eun Hee who exactly look like her..Eun Hee is a very smart girl just like her sister.Unlike her sister,she is very cheerful and not that kind as her sister.She has feelings for Sung Jo too,whom she always sees in her dreams.But she started to envy her sister when she founds out that Sung Jo was