Yasushi Inoue (1907-1991) was one of Japan's finest historical novelists. Works such as "Lou-lan," "Tun-huang" and "The Roof Tile of Tempyo" established his reputation and are still in print. Among his most popular successes are the fictionalized biographies of Confucius and Genghis Khan, and the 1959 "Furin Kazan" is still much admired.
The title refers to the famous war banner of Takeda Shingen (1521-1573). It contained four Chinese characters that signified: "Silent as a forest. Swift as the wind. Rapacious as fire. Immovable as a mountain." These qualities summarized the art of war for the Chinese general Sun Tzu (sixth century B.C.) -- qualities also deemed necessary for military success during the civil wars that defined the Sengoku Period and eventually resulted in a unified Japan.
Among the would-be unifiers (along with Oda Nobunaga and Toyotomi Hideyoshi) was Takeda Shingen, and his noble failure is among the most popular Japanese historical chronicles.