Believing that they need a Japanese martial artist to go undercover, the New York City police turn to an unorthodox officer named Toshi (Tôru Nakamura). Toshi successfully infiltrates "the Brotherhood," gaining the trust of its leader, Hawk (Chad McQueen), and winning the love of Hawk's sister, Maria (Mira Sorvino). As Toshi gathers evidence of the gang's arms-smuggling activities, his bond with Hawk and Maria grows, but other gang members begin to suspect his true identity.