Nine Allied nations signed the Japanese Instrument of Surrender in Tokyo Bay.
The signatories represented the United States, China, the United Kingdom, the Soviet Union, Australia, Canada, France, the Netherlands, and New Zealand. General Douglas MacArthur signed first for the Allied powers, followed by Fleet Admiral Chester Nimitz as the United States representative.
The Japanese document was signed by Mamoru Shigemitsu for the government and General Yoshijiro Umezu for Imperial General Headquarters. The Allied representatives then signed in a prescribed order, reflecting the coalition that had fought Japan across the Pacific and Asia.
The number nine refers to Allied countries, not the total number of people who signed. There were also two Japanese signatories and numerous other Japanese delegates present. Additional surrender ceremonies took place later in locations including Nanking, Singapore, and the Philippines.