Who signed Japan’s surrender document first on September 2, 1945?

Mamoru Shigemitsu signed Japan’s surrender document first on September 2, 1945.

Shigemitsu was Japan’s foreign minister and signed the Japanese Instrument of Surrender on behalf of the emperor and the Japanese government. He signed at about 9:04 a.m. aboard USS Missouri in Tokyo Bay.

General Yoshijiro Umezu signed next for Imperial Japanese General Headquarters. The two men represented Japan’s civilian government and military command, respectively, reflecting the authority of both institutions in the surrender ceremony.

Shigemitsu had previously served as Japan’s ambassador to the United Kingdom and had been a prominent diplomat before returning to the cabinet during the final stage of the war. He signed wearing formal diplomatic dress and using a pen supplied for the ceremony.