The development of Japan's Socialist party since V.J. Day may logically be considered in three periods. The first period, that of reorganization, began in August, 1945, and continued until the first post-war election in April, 1946. The second period comprised the months between April, 1946, and June, 1947, during which Socialists were gathering strength in the chief opposition party. The third period, from May, 1947, to February, 1948, saw the revolutionary passage of Japan's government into the hands of a Socialist-led cabinet.
Left-Wing Realignment: August, 1945–April, 1946. Against a background of military defeat, dissolution of war-time political agencies, and resulting efforts at political realignment should be set the movement which led to formation of the present Shakaito (Social Democratic party). By late August of 1945, the political ferment was active; by early September, Tokyo papers were reporting that remnants of the old proletarian and agrarian organizations—Ronoto (Laborers' and Farmers' party), Nominto (Farmers' party), and Shakai Taishuto (Social Mass party)—were already drawing the lines of the new party formation.