Samurai (1945)

"Innocently pronounced SAM-UR-I and means the Vilest Practices of Inhuman Beings!"

A young Japanese-American orphan in California is taken in by a priest who is actually a Japanese secret agent and a samurai warrior. Due to the samurai's training, the boy murders his English teacher, kills the American parents who have adopted him, smuggles Japanese secret plans into the country, and eventually becomes the governor of California with plans to infiltrate Japanese spies into the state so they can take over.