Beigang teens A-guo and A-douzi fight, loaf, and cause trouble all day. One day, they accidentally grab a bag with guns and drugs, and head for Taipei looking for Brother Jie, a friend in the underworld there.

A-Kuo and A-Tou are teenage boys living in an industrial town in Taiwan. When they are not in school, they generally hang out with their buddy Hsiao Kao, a very stylish and charismatic younger gangster who enjoys their company and support. When one of Hsiao Kao's gangland patrons is gunned down, the trio set out to revenge the killing. As a result, the two teens are forced into hiding. One boy tells his dad he wants to go to America, which nearly kills the old man. The other just lays low. When things cool down a bit, they head on up to Taipei, looking for their gangster friend and sampling the gritty pleasures of the capital city's underworld and nightlife.