"You will regret breaking my heart." Choi Yena was a chubby little girl who fell in love with a beautiful girl named Jo Yuri. The two have been best friends since birth until that one horrific day Yena tells Yuri how she feels and gets coldly rejected. After that day Yena disappears and vows to get revenge on Yuri for breaking her heart. She plans to win Yuri's heart with a new identity and plans to break her heart just like how she had her heart broken.