G.I. Samurai (戦国自衛隊, Sengoku jieitai (Time Slip) and Sengoku Self Defense Force) is a 1979 Japanese feature-length film focusing on the adventures of a modern-day Japan Ground Self-Defense Force (JGSDF) team that accidentally travels in time to the Warring States period (戦国時代, Sengoku jidai). The film stars one of the top male Japanese actor Sonny Chiba and was based on a novel by Ryo Hanmura, a well-known writer of historical novels and science fiction.