G.I. Samurai (戦国自衛隊, Sengoku jieitai, Sengoku Self Defense Force) aka Time Slip, is a 1979 Japanese science fiction/action film focusing on the adventures of a modern-day Japan Ground Self-Defense Force (JGSDF) and Japan Maritime Self-Defense Force (JMSDF) team that accidentally travels in time to the Warring States period (戦国時代, Sengoku jidai). The film stars Sonny Chiba, one of the top male Japanese actors, and was based on a novel by Ryo Hanmura, a well-known writer of historical novels and science fiction. A remake was theatrically released in Japan in 2005 under the title Samurai Commando: Mission 1549.