You know instead of having his Master move to Vietnam after the war cause land was cheap. And then some mook getting on plane and paying this guy to train him, it'd be cooler if the Master was exiled from Japan after World War 2 for not accepting American occupation. Then the Vietcong leaves Zero, who was a member of an elite Special Forces group, for dead after wiping out his squad. He is saved by this Master, who then agrees to teach him. The master learns that not all Americans are blue eyed devils while Zero learns the ancient arts.
Meanwhile back in American a rival Mob family kills off all of Zero's family in attempt to gain soul control of the city. Hearing rumors of a surviving member of the family in Vietnam, they track him down, but kill his master instead. So Zero returns to the states to not only avenge his family and Master, but to reclaim his rightful place as the Don of the Mafia.
Now that's a movie right there.