Young boy Jung-gu is interested in making and sending homemade bombs to people he thinks they may find the bombs useful. He teams up with Hyo-min, the first person to actually explode one of them. Because of carelessness, Hyo-min stimulates pugnacious tendencies that Jung-gu has tried hard to dominate. As a result, Jung-gu is out of his control, kills the inspector and blames Hyo-min for all his crimes.