After two attempts at universal exhibitions were cancelled: in 1912 following the death of the Meiji emperor and then in 1940 because of the war; it was in 1964 that Gisen Sato, governor of Osaka and Daizo Odawara, President of the Chamber of Commerce and Industry, asked the Japanese government to hold an international exhibition in Osaka.
At the beginning of 1965, the government's approval was not long in coming and so was the decision to hold the first Japanese International Exhibition on Senri Hill.
As for the financing and control of Expo70, the Japanese government took care of both aspects on its own, which allowed work to begin in March 1967.
Osaka took the opportunity to modernise its infrastructure to improve living conditions and protect the environment, but this renovation cost $2.3 billion.
The theme of this exhibition was technological progress, but not to glorify new technologies, but rather to educate and pacify. To support this approach, the 77 nations present were invited to propose discussions on various themes, all of which focused on a peaceful future.
Kenzo Tange designed the layout of Expo 70, the site was divided into two zones, the southern zone housed the "exposland" amusement park and the administration, while the Japanese garden and pavilions were located in the north. The two areas were connected by a 1 km long path. With his ideal urban concept of a flowering tree, Kenzo Tange envisioned an ideal city in the exhibition. This was greatly facilitated by the fact that the regulations did not provide for any limitations or constraints on the pavilions, which allowed the participants to develop their creativity to the fullest; indeed, most of the large Japanese companies did not deny themselves this pleasure.
On 14 March 1970, as planned, the Emperor and Empress of Japan opened Expo 70.