Born Feb. 11, 1908, in Shizuoka Prefecture. Figure in the Japanese Social Democratic movement.
Katsumata graduated from the department of economics of the University of Kyoto in 1931 and then served in a number of governmental institutions. He has been a member of the Socialist Party of Japan (SPJ) since 1947. As a candidate of the SPJ, hehas been repeatedly elected to the Diet. After the split of the SPJ in 1951 into the Left SPJ and the Right SPJ, Katsumata playeda prominent role in the Left SPJ. At the Unification Congress in 1955, he was elected a member of the central executive committee of the SPJ, in which he occupied a number of leading positions from 1955 to 1967. He was chairman of the centralexe cutive committee of the SPJ in 1967–68 and has been a party advisor since 1968.