[2] After early coalition negotiations, Socialist Komakichi Matsuoka was elected Speaker of the lower house on 21 May, Democrat Man'itsu Tanaka Vice-Speaker.

SCAP Douglas MacArthur welcomed the choice, thereby reducing resistance by some politicians to a Socialist-led coalition government.

The new government enacted several reforms sought by the SCAP, such as the dissolution of the powerful Home Ministry and anti-trust legislation to dismantle the zaibatsu.

After an even shorter government under Katayama's deputy, Democrat Hitoshi Ashida, the coalition collapsed, and Liberal Shigeru Yoshida returned as prime minister in October 1948 by which time the Liberals (reformed as Democratic Liberal Party in March 1948) had gained the position as first party in the lower house by defectors from the Democratic Party and independents joining, though by far not an absolute majority.

In December 1948, Yoshida staged a no-confidence vote (under the prevailing (SCAP) interpretation of the Constitution at the time, the House of Representatives could only be dissolved under the provisions of article 69;[5] referred to in Japanese as nareai kaisan (馴れ合い解散, "collusive dissolution")) to gain an outright DLP majority in the ensuing 1949 lower house election.