Kazuhira Miller, also known as Kaz, is a key strategist and second-in-command to Big Boss in the Metal Gear Solid series. He is known for his tactical genius and strong dedication to the cause of creating a world where soldiers can determine their own fate. Born in Japan to mixed Japanese-American heritage, Miller's complex personality balances a hardened soldier's resolve with moments of vulnerability. Throughout the series, Kaz plays a crucial role in establishing and running Militaires Sans Frontières, and later, Diamond Dogs, shaping the path of Big Boss's legacy.