Lucy gets bullied and humiliated by her biggest crush, Kim Jongin. Taemin, will do anything to stop the past from happening again, even if it means killing the people he loves. But what will Kai do? Will he betray his best friend and protect the girl that he hates the most? But the real question is: Will Kai be able to do it without falling in love?  

She's a student from the States. He's a teacher at Sung Ju High School, where she attends. How will they both cope when they are arranged to a marriage made a long time ago?