Ghost Dog: The Way of the Samurai (1999)

An African-American Mafia hit man who models himself after the samurai of old finds himself targeted for death by the mob. Jarmusch's spiritual gangster film tells the story of an inner-city hit man (Whitaker) who lives on a rooftop, training himself as a samurai in the strictest sense. He communicates primarily by carrier pigeon, while remaining loyal to a gangster (Tormey) who once saved his life.

Source: TMDb