Sukotjo was born on 18 December 1927 in Kertosono, Java. After the surrender of Japanese forces in Indonesia in 1945, Sukotjo obtained one of the rifles the Japanese left behind. "At the moment I just started fighting" he has said about the start of his involvement in the war. On 9 August 1947 he finished his training as an officer at the rank of vaandrig (officer cadet). At that point he joined the bodyguard of Sukarno and was with him during his surrender at Yogyakarta. In 1952 Sukotjo had reached the rank of Lieutenant. He retired from the military at the rank of Major general.
