Jung Yong Hwa and Park Shin Hye are childhood friends....Yong Hwa loves to be around shin hey but shin hey always avoid him in school and before her friends.......A beautiful Friendship turned into a hateful relationship going to the extreme of taking Revenge......

Jung Yong Hwa: A lonely brilliant boy in school loved by his teachers and hated by his classmates because of his looks and calm character .Park Shin Hye's childhood and family friend went to USA  while studying in Mid School because of Family reason and park shin hey , coming back to his homeland after 5 years to get his revenge.....

Park Shin Hye : A sweet care freegirl, Loved by her friends  , Jung yong Hwa's childhood and family friend.....always avoid yong hwa in school and before her friends, Misses yong hwa after he left her...Waiting back for yong Hwa to restart their friendship....

Krystal Jung: Yong hwa's twin sister, Became close with park shin hey after transferring to her brother school during 7th grade.

Shin Hye's and krystal close friend: 

* Kim Ji won 

Yong Hwa's close friends:

* Lee jong Hyun

* Kang Min hyuk

* Lee Jung Shin

* Seohyun