A four-character idiom meaning 'as swift as the wind, as silent as the forest, as fierce as fire, and as immovable as a mountain,' expressing a military tactic or spirit (famously used by Takeda Shingen).
彼は部下に『風林火山』の精神で仕事を進めるよう指示した。
He instructed his subordinates to proceed with their work in the spirit of 'Fūrinkazan'.
戦国時代、武田信玄は旗印に風林火山を掲げたことで知られる。
Takeda Shingen is known for having displayed 'Fūrinkazan' on his banner during the Warring States period.