Katayama Cabinet
The Katayama Cabinet governed Japan under the leadership of Prime Minister Tetsu Katayama from May 1947 to March 1948. It was the first cabinet under the postwar constitution.
The Japan Socialist Party had emerged as strongest party from both the 23rd lower house election and the 1st upper house election. However, the formation of a coalition proved difficult as any majority coalition would involve at least two of the three largest parties. While the Socialists offered the conservative Japan Liberal Party of incumbent prime minister Shigeru Yoshida a grand coalition, Yoshida refused active participation in the government. Under the new constitution, the prime minister was no longer selected by the Emperor, but elected by the Diet, "before the conduct of any other business" – and the Socialists pushed for an early vote to prevent the other two major parties from excluding them from a ruling coalition: on May 23, Socialist Tetsu Katayama was elected almost unopposed while the coalition negotiations were still in progress. When Katayama formally became prime minister on May 24 after his ceremonial investiture by the Emperor, he technically held all ministerial posts – a so-called "one-man cabinet". The JLP still refused cooperation, and the JSP eventually agreed on a coalition with the Democratic Party and the National Cooperative Party. Together, the three parties held a solid majority in the HR, and were able to control the HC given the fact that the largest group there, the Ryokufūkai formed by independents, was willing to support the government. The other cabinet members were eventually appointed on June 1. The cabinet initially consisted of seven Socialists, eight Democrats, two Cooperativists and one Ryokufūkai member.
After conflicts over price controls and taxes, the left wing of the Socialist Party threatened to block the budget for fiscal 1948, and in February 1948, Katayama resigned. Deputy prime minister Hitoshi Ashida was elected on February 21 to succeed him, the Katayama Cabinet remained in office until his investiture on March 10. The three-party coalition of Socialists, Democrats and Cooperativists continued under Democrat Ashida, however the Ashida Cabinet would be engulfed by the largest corruption scandal of the occupation period and last even shorter.
| Portfolio | Minister | Party | Diet membership |
| Prime Minister | Tetsu Katayama | JSP | HR, Kanagawa 3 |
| Deputy Prime Minister Foreign Affairs | Hitoshi Ashida | DPJ | HR, Kyōto 2 |
| Internal Affairs Construction | Kozaemon Kimura | DPJ | HR, Shimane At-large |
| Finance | Shōtarō Yano | DPJ | HR, Kagawa 2 |
| Finance | Takeo Kurusu | Ryokufūkai/JLP | HC, Yamaguchi |
| Justice Justice | Yoshio Suzuki | JSP | HR, Fukushima 2 |
| Education | Tatsuo Morito | JSP | HR, Hiroshima 3 |
| Health and Welfare | Sadayoshi Hitotsumatsu | DPJ | HR, Osaka 1 |
| Agriculture and Forestry | Rikizō Hirano | JSP | HR, Yamanashi At-large |
| Agriculture and Forestry | Tetsu Katayama | JSP | HR, Kanagawa 3 |
| Agriculture and Forestry | Kanae Hatano | JSP | HC, Fukuoka |
| Commerce and Industry | Chōzaburō Mizutani | JSP | HR, Kyōto 1 |
| Transport | Gizō Tomabechi | DPJ | HR, Aomori 1 |
| Transport | Tokutarō Kitamura | DPJ | HR, Nagasaki 2 |
| Communications | Takeo Miki | NCP | HR, Tokushima At-large |
| Without portfolio Labour | Mitsusuke Yonekubo | JSP | HR, Hyōgo 2 |
| Economic Stability Prices | Ryokufūkai | HC, National | |
| Demobilization Without portfolio Reparations | Junzō Sasamori | NCP | HR, Aomori 2 |
| Administrative oversight | Takao Saitō | DPJ | HR, Hyōgo 5 |
| Without portfolio Local finance | Giichi Takeda | DPJ | HR, Ishikawa 1 |
| Without portfolio Chief Cabinet Secretary | Suehiro Nishio | JSP | HR, Osaka 2 |
| Without portfolio | Heima Hayashi | DPJ | HR, Fukushima 2 |