The stage is set in New York's Upper West Side in the 1950s, where the area's slums are plagued by racial tensions acted on by two rival gangs: the Puerto Rican Sharks and the Caucasian Jets. In the middle of this mess is young, innocent Maria, a Puerto Rican seamstress whose brother, Bernardo, is the leader of the Sharks. Despite the warnings of Anita, Bernardo's fiery girlfriend, Maria falls ...