Jackson is a delinquent but he has a soft side that he doesn't show many people. One day, on his way home from school he finds a stray puppy and takes him in. Next morning he finds a cute boy in his bed where the dog was (Nichkhun)!!? Jackson then beginning his journey to help the boy become human, love and drama happens when the Jackson's crush on classmate Bambam intensifies, but Nichkhun suddenly feel pain in his heart(?) "What is this feeling?"