Kōno aspired to become prime minister, but although he held a large number of important party and cabinet positions, reflecting his power and influence, he was not able to rise to the premiership before his death in 1965.

Kōno was born in 1898 to a wealthy farming family (gōnō) in Toyokawa village, Ashigarashimo District, Kanagawa Prefecture (present-day Naruda, Odawara City).

His father, Jihei Kōno, served successively as mayor of Toyokawa, a member of the district council, and chairman of the Kanagawa Prefectural Assembly.

In 1956, Kōno founded a "study group" called the "Spring and Autumn Society" (春秋会, Shunjūkai), which became the basis of his powerful personal faction in the Diet.

In 1959, Prime Minister Nobusuke Kishi made it clear that he intended to seek an unprecedented third term in office, in violation of a longstanding norm that Japanese prime ministers serve only two terms before stepping aside to make way for the next person in line.

[2] To facilitate this, Kishi signed a secret written agreement with Kōno, also co-signed by fellow faction leaders and LDP heavyweights Eisaku Satō and Banboku Ōno, stating that Ōno would be the next prime minister after Kishi's time in office concluded, followed in turn by Kōno and Satō, in exchange for all three leaders vocally supporting Kishi's administration and his bid for a third term.

The Olympics were hailed by the Japanese media and around the world as a great success, winning Kōno praise for his effective management.