Ka-Ran and Nam-Joon were classmates in elementary school. Ka-Ran is a tomboy who prefers trousers to skirts, and loves taekwondo more than her piano lessons. Nam-Joon on the other hand is Mr. Perfect and Wonderful whoâÃÂÃÂs got the good looks and the fine brain. No doubt, he is the most popular guy among the girls. One day, Ka-Ran witnesses the scene where Nam-Joon gives away the sweet bun which he got from Ka-RanâÃÂÃÂs friend to another girl. Ka-Ran throws herself at Nam-Joon and beats him up. From that on, their ÃÂnightmare begins.