Ichirō Hatoyama
After the end of the occupation of Japan, Shigemitsu formed the short-lived Kaishintō party, which merged with the Japan Democratic Party in 1954. In October 1952, he was elected to a seat in the Lower House of the Diet of Japan, and in 1954, he became Deputy Prime Minister of Japan under Prime Minister Ichirō Hatoyama, the leader of Japan Democratic Party. The cabinet continued after the merger of JDP and Liberal Party as the Liberal Democratic Party (LDP) in 1955, and Shigemitsu continued to hold the post of Deputy Prime Minister of Japan until 1956.