SM wants Exo's popularity to explode so what better way than to get one of the members to date Baekhyun's cousin, Hyomi (who is in a fairly popular K-pop group). That member happens to be Kris. Kris and Hyomi are the same, they both give off a cold appearance but are really dorky. That causes them to heads. Hyomi isn't a fan of Exo so she doesn't know the members as much other than Luhan (who she had befriended before). 

(B.A.P is also in this story as friends of Hyomi and there's mentions of other K-pop groups)