Donghae and Eunhyuk are one of the best couple in highschool, but when a secret is revealed between Jessica and Donghae sleeping together before they became a couple Eunhyuk was furious and decide to revenge by attempting to sleep with Siwon Donghae's bestfriend but stoppped with Siwon feeling guilty, apologized to Eunhyuk, the next day they tried to make amends but when Donghae learned from Eunhyuk that he kissed Siwon, Donghae is so upset and break-up with him. With being heartbroken and trying to forget Eunhyuk he turns on to Yoona his girlfriend during their freshmen year and rekindled their love, but Eunhyuk never want to give up how can he make things right?