Fukurō no Shiro

Fukurō no Shiro (梟の城, Owls' Castle) is the ninja-themed 1959 debut novel of Japanese author Ryōtarō Shiba, which won him the Naoki Prize in 1960 after the story was published by Kodansha. It was later made into two jidaigeki-genre films, Castle of Owls in 1963 and Owls' Castle in 1999.

Castle of Owls (忍者秘帖・梟の城, Ninja Hichō Fukuro no Shiro^?), literally "Owls' Castle Ninja Secret Handbook", also known as Samurai Spies (not to be confused with the unrelated film Samurai Spy), is a 1963 film directed by Eiichi Kudō. It starred Ryūtarō Ōtomo (as Juzo), Minoru Ōki (as Gohei), Hizuru Takachiho (as Kohagi), Chiyoko Honma (as Kizaru) and Choichiro Kawarazaki (as Kumotaro) in the main roles. The film is much less known than its remake.

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