Obuchi was born in Gunma Prefecture on June 25, 1937, as the second son of a yarn mill owner. His birth date is just one month away from that of Hashimoto, and the two men entered parliament in the same year. They have also been elected the same number of times, and have worked hard together, positively influencing each other throughout their political careers as close colleagues of the same LDP faction.

Obuchi entered the School of Literature of Waseda University in April 1958. Following the sudden death of his father in August of the same year, he secretly resolved to become a politician so as to fulfill his father's aspirations. He joined Waseda University's debating society, which has been a training ground for many politicians, in order to hone his speaking skills. In March 1962 he graduated with a degree in English literature and stayed at Waseda, where he commenced postgraduate studies in political science. In the following year he embarked on a world trip alone, with the determination that a politician should know the world.

From Okinawa Obuchi traveled throughout Asia, including Thailand, Pakistan, India, and Sri Lanka. He then visited Iran, Kuwait, Saudi Arabia, and Africa. Subsequently he traveled from the United Kingdom to the United States, and thence to Brazil, Uruguay, and Argentina. By the time he returned to Japan in September 1963, Obuchi had visited 38 countries over a nine-month period.

Two months after his return to Japan, Obuchi stood as a candidate in the November 1963 election for the House of Representatives and was elected as the member from Gunma Prefecture's Third District. Then aged 26, he was the nation's youngest Diet member. In 1970, during his third term, he was appointed Parliamentary Vice-Minister of Posts and Telecommunications. After serving also as Parliamentary Vice-Minister of Construction, in 1973 he was appointed Deputy Director General of the Prime Minister's Office. Also in 1973, Obuchi visited Thailand and other Southeast Asian countries as a special envoy of the prime minister to develop concrete plans for the Ship for Southeast Asian Youth Program.

Obuchi's first cabinet appointment came in November 1979, when he joined the second cabinet of Prime Minister Masayoshi Ohira as concurrently Director General of the Prime Minister's Office and Director General of the Okinawa Development Agency. Noted for a friendly temperament that has made him popular, Obuchi is known by the nickname "Mr. Personality." It is perhaps because of this quality that he has been able to serve as chairman of key committees that have been the focus of dramatic clashes between the government and the opposition, including the House of Representatives Special Committee on Security in 1982 and the House of Representatives Committee on the Budget in 1986.

When Prime Minister Noboru Takeshita formed his cabinet in November 1987, Obuchi was appointed as Chief Cabinet Secretary, making him the prime minister's right hand and spokesman for the cabinet. During this period he played a discreet but important role in a number of major events, including the funeral of Emperor Showa, the accession of Emperor Akihito, and the adoption of "Heisei" as Japan's new era name.

Thereafter Obuchi devoted much of his efforts to parliamentarian-level diplomacy. In 1990 he undertook a very full program of overseas travel, starting with visits to the Soviet Union in January and Brazil in March. In June he traveled to the United States to attend ceremonies for the thirtieth anniversary of the Japan-U.S. Security Treaty. A visit to Turkey in July was followed by a trip to the Soviet Union as leader of an LDP mission in September. In November he visited China.

In April 1991 Obuchi took office as Secretary General of the LDP. The July 1993 general election left the LDP far short of a majority, and it was relegated to the opposition benches. Obuchi managed to bring the group of Diet members formerly led by former Prime Minister Takeshita back together and emerged as its leader. In June 1994 the LDP, the Social Democratic Party of Japan, and New Party Sakigake formed a three-party coalition cabinet under Prime Minister Tomiichi Murayama (Chairman of the SDPJ). LDP President Yohei Kono joined the cabinet as Foreign Minister, and in July Obuchi was promoted to the party vice-presidency, becoming in effect one of the LDP's top decision-makers.

In the LDP presidential election of September 1995, Obuchi actively supported the candidacy of Hashimoto, who was a member of the group of Diet members led by Obuchi. Obuchi was the main driving force behind Hashimoto's election as party president and the formation of the Hashimoto cabinet in January 1996.

At a press conference following his appointment, the new Minister for Foreign Affairs was asked about the settlement of a peace treaty with Russia, which is an issue still left over from World War II. Obuchi expressed his resolve to do his utmost to settle the matter before the end of the century. Clearly the time was right for Obuchi's appointment as Foreign Minister.

Obuchi and his wife, Chizuko, have one son and two daughters.