LDP President and Prime Minister Keizo Obuchi fell ill soon after he returned from the meeting with Mr.Ichiro Ozawa, the then president of the Liberal Party, at midnight of April 1st, and was hospitalized immediately. The executives of the Party discussed their response to the situation and decided to convene a Joint Plenary Meeting of Party Members of both Houses of the Diet, which would take the place of the Party Convention, to elect its president. On April 5, the then Secretary General Yoshiro Mori was elected at the Joint Plenary Meeting and became the 19th President of the Party.
Mr.Mori stated his determination at his inaugural President's Address: “I commit myself to making the G-8 Okinawa Summit Meetings successful and fruitful, for which the late President Obuchi dedicated himself tirelessly but with the ultimate cost of his health. I will also make every effort to revive the Japanese economy.” On that day, the Mori Cabinet was formed and the Mori administration launched.

In his general policy speech in the National Diet on April 7th Prime Minister Mori appealed to the public to work together to create a Japan “in which we can live safely with dreams”, “a beautiful nation with heartfelt and considerate people”, and “a nation trusted by the world.” Mori Cabinet's toughest challenge was the revival of the economy. He proposed “born-again Japan” as a catchphrase that encapsulated his hopes and energies for the future of Japan and its people.

He particularly directed his attention to the IT revolution which would have a profound influence on Japan's economy and society, and endorsed the enactment of the IT fundamental law. He introduced”e-Japan strategy” as a national strategy, whereby the government and the private sectors work hand in hand to promote IT revolution. In addition, the Mori administration put a great deal of effort into the reform of the education system and introduced bills related to education reform to the Diet.

On July 28, he proposed a detailed program for the reconstruction of Japan “born-again Japan,” in his general policy speech before the Diet: They were, “born-again economy,” “born-again social security,” “born-again education,” “born-again governments,” and “born-again diplomacy.”

On January 31, 2002, the first day of the plenary session, he announced Japan's visions for the 21st century before the Diet; that is, he hoped that the 21st century would be “the century of hope”, “the century for humanity”, “the century of trust”, and “the century for the globe.”

Among his diplomatic achievements, he served as the chairman of the G-8 Kyushu/ Okinawa Summit the success of which was an earnest wish of the late President Obuchi. At the meeting, Mori announced he Groups' determination to the world: “We discussed what we should do to enable people in the world to enjoy greater prosperity, to attain peace of mind, and live in a more stable world.” In addition, he deepened friendly relations with other Summit member countries and cultivated cooperative relations.

Prime Minister Mori held summit talks between Japan and the U.S., and then between Japan and Russia soon after. At the Japan-U.S. summit talks, President Bush and Prime Minister Mori pledged to create an atmosphere for a new alliance and establishment of mutual trust. He held summit talks with Russian President Putin as many as six times in a one- year period and built strong personal ties with the Russian leader. President Putin and Prime Minister Mori stated in their joint communique, the Irkutsk Statement of March 25, that the stage was set where they could discuss concrete measures toward concluding the peace treaty and working toward the return of the four Northern Islands to Japan.

He also visited African nations, sub-Saharan Africa, for the first time as Japanese Prime Minister. Setting an example with regard to “human security”, he broadened Japan's international stance, which resulted in improving its credibility in the world.

On April 18, President Mori held a press conference in the lead-up to the general election for the House of Councillors in summer and announced his resignation as premier. On April 24, the Party presidential election was held and Junichiro Koizumi was elected the 20th President.