Choi Su Jin is Choi Siwon’s youngest sister. She was adopted by the Choi Family when she was 5 years old. When her older brother Siwon got into Super Junior she had a crush on Cho Kyuhyun the maknae of the group. Her brother was against it because he had to face Kyuhyun all the time and because he wanted to protect his sister. But they got together anyway. 2 years they had been dating and Su Jin was sended to America to study law and kyuhyun and Su Jin ended their relationship. Terrible things happened there in America and Su Jin finally could come back. But she was a different girl now. She wasn’t as friendly anymore, she wasn’t as happy like she had been before. Her style had changed and it was like her heart had become a block of ice. No one knows what had happened. At that time SM had debuted a 12 member boy group: EXO. Slowly she starts to like one of them. Can he melt her heart again? And what about Kyuhyun who still waits for Su Jin to be his again?