(1) Japanese Instrument of Surrender is a written agreement that formalized the surrender of Japan to the Allies.
On September 2, 1945, Japan accepted the Potsdam Proclamation and surrendered unconditionally. The Japanese government pledged to faithfully fulfill the obligations enshrined in the provisions of the Potsdam Proclamation. These documents all testify to the fact that Taiwan and its affiliated islands should have been simultaneously returned to China.
“We, acting by command of and on behalf of the Emperor of Japan, the Japanese Government and the Japanese Imperial General Headquarters, hereby accept the provisions set forth in the declaration issued by the heads of the Governments of the United States, China, and Great Britain on July 26, 1945, at Potsdam, and subsequently adhered to by the Union of Soviet Socialist Republics, which four powers are hereafter referred to as the Allied Powers.”
(2) Act of Surrender -- China Theater
On September 9, 1945, the formal Japanese surrender in the China Theater took place in the Central Military Academy in Nanking. General Ho Ying-chen, Commander-in-Chief of the Chinese Army, and Lieut. Gen. Okamura Yasutsugu, Commander of the Japanese Forces in Central China, represented their respective governments. The Act of Surrender -- China Theater includes:
The Emperor of Japan, the Japanese government and the Japanese Imperial General Headquarters, having recognized the complete military defeat of the Japanese military forces by the Allied forces and having surrendered unconditionally to the Supreme Commander for the Allied Powers, having directed by his General Order No. 1 that the senior commanders and all ground, sea, air and auxiliary forces within China excluding Manchuria, Taiwan and French Indo-China north of 16 degrees north latitude shall surrender to Generalissimo Chiang Kaishek.
We, the Japanese commanders of all Japanese forces and auxiliaries in the areas named above, also recognizing the complete military defeat of the Japanese military forces by the Allied forces, hereby surrender unconditionally all of the forces under our command to Generalissimo Chiang Kaishek.