In Akira Kurosawa's classic 1980 film "Kagemusha" ("Shadow Warrior"), the 16th-century daimyo Takeda Shingen is mortally wounded by a sniper after being lured by the sound of a flute during a castle siege. Takeda's clan know that rival warlords Oda Nobunaga and Tokugawa Ieyasu will pounce on their domain...