Big Bang () is a 2007 South Korean action-comedy film written and directed by Park Jung-woo, and starring Kam Woo-sung and Kim Soo-ro.
Park Man-su is an ordinary salaryman who lives his life according to a strict set of rules, and this lack of flexibility makes him hard to like at home and at the office. One day, his wife asks for a divorce because she's bored with their life, and he is fired because his corrupt boss hates him. So on his way home, the frustrated and outraged Man-su tries to set himself free by breaking all the rules that have restricted him his entire life by deviating from them, just for one day. He swears at passers-by, kicks signboards and pees on the street, and he is soon placed under arrest by Ma Dong-cheol, a demoted but zealous cop. Officer Ma takes him to the police station to teach him a lesson, where Man-su meets Yang Cheol-gon, a career criminal with 15 previous convictions, who finds it more comfortable to be behind bars. Cheol-gon incites the desperate and timid Man-su to escape the police station with him, and through a series of mishaps, they happen to steal a gun and police car, with which they also try their hand at punishing "law dodgers" themselves. With Officer Ma in hot pursuit, Man-su and Cheol-gon find themselves branded as antisocial vigilantes, and the fine for Man-su's original misdemeanor has now turned into a potential life sentence. Thus, the unlikely pair spend a wild night together in Seoul.