One-year-old Nakasone (1919)
Nakasone was born in Takasaki in Gunma, a prefecture northwest of Tokyo, on 27 May 1918. He was the second son of Nakasone Matsugoro II, a lumber dealer, and Nakamura Yuku. He had five siblings: an elder brother named Kichitaro, an elder sister named Shoko, a younger brother named Ryosuke and another younger brother and younger sister who both died in childhood. The Nakasone family had been of the samurai class during the Edo period, and claimed direct descent from the Minamoto clan through the famous Minamoto no Yoshimitsu and through his son Minamoto no Yoshikiyo (d. 1149). According to family records, Tsunayoshi (k. 1417), a vassal of the Takeda clan and a tenth-generation descendant of Yoshikiyo, took the name of Nakasone Juro and was killed at the Battle of Sagamigawa. In about 1590, the samurai Nakasone Sōemon Mitsunaga settled in the town of Satomimura in Kōzuke Province. His descendants became silk merchants and pawnbrokers. Nakasone's father, originally born Nakasone Kanichi, settled in Takasaki in 1912 and established a timber business and lumberyard which had success as a result of the post-First World War building boom.
Nakasone described his early childhood and youth as a happy one, and himself as a "quiet, easy-going child" nicknamed "Yat-chan". He attended a local primary school in Takasaki and was a poor student until the fourth grade, after which he excelled and was at the top of his class. He entered Shizuoka High School in 1935, where he excelled in history and literature, and learned to speak fluent French. In the autumn of 1938, Nakasone entered Tokyo Imperial University. During World War II, he was a commissioned officer and paymaster in the Imperial Japanese Navy. He later wrote of his return to Tokyo in August 1945 after Japan's surrender: "I stood vacantly amid the ruins of Tokyo, after discarding my officer's short sword and removing the epaulettes of my uniform. As I looked around me, I swore to resurrect my homeland from the ashes of defeat".
In 1947, he gave up a promising career in an elite government ministry to run for Parliament with the belief that in its postwar remorse, Japan was in danger of discarding its traditional values. He campaigned on a nationalist platform, arguing for an enlarged Self-Defence Force, to amend Article 9 of the Japanese Constitution (which outlawed war as a means to settling international disputes), and to revive Japanese patriotism, especially in reverence for the Emperor. He entered the Diet of Japan as a member of the House of Representatives for the Democratic Party. "As a freshman lawmaker in 1951, he delivered a 28-page letter to General MacArthur criticising the occupation, a brazen move. The General angrily threw the letter in [the] bin, Yasuhiro was later told. This stand established [Yasuhiro Nakasone's] credentials as a right-wing politician." He gained brief notoriety in 1952 for blaming Emperor Hirohito for Japan's defeat in the war. In 1955, at Nakasone's urging, the government granted the equivalent of $14,000,000 to the Agency for Industrial Science and Technology to begin nuclear power research. Nakasone rose through the LDP's ranks, becoming Minister of Science in 1959 under the government of Nobusuke Kishi, then Minister of Transport in 1967, Director General of the Japan Defense Agency from 1970 to 1971, Minister of International Trade and Industry in 1972 and Minister of Administration in 1981.
As the head of the Self-Defence Force, Nakasone argued for an increase in defence spending from less than 1% GDP to 3% of GDP. He was also in favour of Japan having tactical nuclear weapons. He was labelled "the weathervane" in 1972 because he switched his support from Takeo Fukuda to Kakuei Tanaka in the leadership election, ensuring Tanaka's victory. In turn, Tanaka would give his powerful support to Nakasone against Fukuda a decade later in the fight for the premiership.