Ichirō Hatoyama
Since 1947, the office of Chief Cabinet Secretary has been regarded as a stepping stone to the post of Prime Minister. The first Chief Cabinet Secretary to become Prime Minister was Ichirō Hatoyama, who served in the position under Tanaka Giichi. Since then, eight other former Chief Cabinet Secretaries have become Prime Ministers, most recently Shinzō Abe, Yasuo Fukuda, and Yoshihide Suga.