Taiwan, 1986. The streets are ruled by small organised gangs, nowhere more so than the older districts. Monga follows the Temple Front gang, a violent punk gang lead by the good-looking tough Dragon, as seen through the eyes of a teen recruit named Mosquito, as the gang evolves from a band of street thugs to organised Mafioso. Along the way the film touches on themes of family, societal change and a little gangland romance.

The title Monga refers to the local name for the Wanhua district of Taipei, the oldest part of Taipei and where the bulk of the film is set.

Monga was a smash hit in its native Taiwan, taking in more at the Taiwanese box office than Avatar during their respective opening weeks (though Avatar remains the top grossing film of all time in Taiwan), and has been hugely popular on the international festival circuit. The film sets itself apart from conceptually similar films, particularly Goodfellas and City of God, with its nostalgic 1980s setting; distinct depiction of the notorious seamy side of Taiwan before its cleanup in the 1990s; and brilliant cinematography.