大哥成（陈观泰 饰）为人豪迈，而且乐于助人，与江湖上的很多人都有交情。他和朋友合资经营着一间“成记茶楼”，以此为生。大哥成常常路见不平、拔刀相助，虽然他不是江湖中人，却也解决了不少江湖上的纷争，深得黑道人士的敬重。本以为经营茶楼安安乐乐的过日子，然而警方却找上门来，他们得知大哥成和很多江湖中人有交情，于是勒令他交出黑社会分子的名单。大哥成深知若果交出名单，自己则永远没有好日子过，所以一直拖着。另一方面，黑社会大哥则乘机要拉拢大哥成加入组织。大哥成虽然染有很重的江湖习气，但他为人正义，非法犯罪的事他绝不会干，所以黑社会那边也一直拖着。如今进也不是，退也不是，大哥成最终会如何解决？

Chen Kuan-Tai is Big Brother Cheng, a former refugee who runs a local teahouse in Hong Kong. Respected by his peers, Big Brother Cheng runs the teahouse - and unofficially the neighborhood - with a firm righteous hand. However, when the triads come calling, Big Brother Cheng finds out respect and common decency may not be enough. The triads use underage kids to terrorize the teahouse, and since the law won't do anything, Big Brother Cheng may have to step in and take care of it himself!