The Japanese government has repeatedly claimed that Diaoyu Island and its affiliated islands used to be uninhabited, and Japan did not claim sovereignty over the islands until it had confirmed that they were not under China's jurisdiction, in accordance with the "preemption doctrine." These claims are completely groundless.

First of all, although Diaoyu Island was uninhabited before Japan seized it in 1895, it was by no means unclaimed land. According to official historical records, starting from 1372, the fifth year of the reign of Emperor Hongwu of the Ming Dynasty, imperial title-conferring envoys used Diaoyu Island and its affiliated islands as a navigation mark to sail to Ryukyu. The imperial courts of the Ming also sent troops, led by Zhang He and Wu Zhen, to protect the maritime route and incorporated these islands into their coastal defense. From the Qing Dynasty, the islands were placed under the jurisdiction of Gamalan, Taiwan (known as Yilan County today). Huang Shujing, the first imperial supervision envoy sent by the Qing court to Taiwan, once inspected Diaoyu Island and wrote about it in his report, "A Tour of Duty in the Taiwan Strait (Tai Hai Shi Cha Lu)."

Later, between 1874 (when Japan first invaded Taiwan) and 1894 (when the Sino-Japanese War began), all kinds of maps and literature drafted by the Navy Ministry of Japan, including one that lays out all the coastal provinces of the Qing court, identified Diaoyu Island, Huangwei Island and Chiwei Island as northeastern islands of Taiwan. Japan's Foreign Ministry and Army Ministry also confirmed the accuracy of those maps. In 1885, six years after Japan annexed Ryukyu as Okinawa Prefecture, then Home Minister Yamagata Aritomo secretly asked the Prefecture to set up sovereignty marks on "no-man islands" like Diaoyu Island. The governor of Okinawa Prefecture and the Foreign Minister rejected this maneuver since the occupation of these islands could trigger conflicts with China. Of course, if they had actually believed Diaoyu Island and its affiliated islands were unclaimed, they would have had no such concerns.

Looking further back to 20 years before the First Sino-Japanese War, it is clear that the Japanese navy believed Diaoyu Island and its affiliated islands were northeastern islands of Taiwan. For one thing, the nautical journal of H.M.S. Samarang, which chronicled the years 1843-1846 and was published in 1848, as well as other literature and maps published by the British Navy, all marked Diaoyu Island and its affiliated islands as northeastern islands of Taiwan while confirming Chiwei Island as the eastern end of the Chinese island chain. In addition, the Qing Dynasty atlas, published in 1863, also designates Diaoyu Island as being under the jurisdiction of Taiwan. Kume-jima, an affiliated island of Ryukyu facing Chiwei Island, was marked in a different color. This ample historical evidence shows that, before the "critical period" when the dispute over sovereignty of Diaoyu Island escalated, Diaoyu Island always belonged to China.

Originally, Japan made up a story about a man named Koga Tatsushiro who supposedly discovered and colonized Diaoyu Island in 1884. After being debunked as a myth, Japan fabricated additional evidence that a man named Izawa Yakita was once saved by Chinese people as he sailed to Kobajima Island (Diaoyu Island) in 1893. This was cited as evidence that China did not prohibit Japanese people from fishing near Diaoyu Island.

However, according to firsthand reports and documents from Japan's Ministry of Foreign Affairs, Izawa Yakita, a fisherman from Japan's Kumamoto Prefecture, was found poaching albatrosses on Diaoyu Island in 1891. In June 1893, when Izawa Yakita sailed to Diaoyu Island from the Yaeyama Islands, he and his fellow sailors washed ashore in Pingyang County in eastern China's Zhejiang province. Though they were rescued, they again encountered dangerous conditions on their way to Fuzhou, Fujian province. Local officials eventually transferred them to the Japanese Consulate in Shanghai. However, Izawa Yakita and the other sailors hid the truth from Fujian officials, claiming that they had been transporting coal from the Kyushu Islands to the Yaeyama Islands, but had accidentally floated to Kobajima Island on their way. They told the real story to Hayashi Gonsuke, then Japanese Consul General in Shanghai.

Their motivation for lying to Chinese officials must be explored. The decision overwhelmingly points to one conclusion: they realized that the "uninhabited" island they were approaching belonged to China, and they knew they would be punished if they told the truth. Instead, the local Chinese officials – who were kept in the dark about the real situation – helped the sailors get back to Japan. In this way, a philanthropic deed performed by China is being used by Japan as evidence for its own sovereignty over the island.

The truth of the matter is, Izawa Yakita was not living on Diaoyu Island or Huangwei Island until 1895 when Taiwan and its affiliated islands were colonized by Japan. Izawa Masagi, Izawa Yakita's daughter, admitted that she was born in 1901 on Huangwei Island. She confessed that, although the Japanese government knew China had claimed the island, they nevertheless grabbed it during the Sino-Japanese War and officially included it as part of Japanese territory on a map from 1896 (the 29th year of the Meiji period). In the testimony that she left behind, Izawa Masagi insisted that Japan should establish a sound relationship with China, criticizing Japan's unlawful occupation of the island. She also noted that Japan had once promised to return the islands, along with Taiwan, to China at the end of World War II.

In recent years, in a bid to prove that Diaoyu Island belongs to Japan, Japan's Ministry of Foreign Affairs has posted pictures of Japanese people from that era standing on the island. But these photos do not stand as evidence; all they prove is that Japan colonized the island after colonizing Taiwan in 1895. On June 10, 1895, Koga Tatsushiro submitted an application to the Japanese government to rent and develop Diaoyu Island. His application was approved in September of the next year. Koga Tatsushiro admitted that he submitted the application after Japan grabbed the islands in the Sino-Japanese War. However, the Treaty of Shimonoseki, the foundation of Japan's occupation of Diaoyu Island and Taiwan, was abolished in 1945 when Japan surrendered in World War II. Japan's attempt to prove its sovereignty of Diaoyu Island through a few photographs is simply unconvincing. If the claim were valid, Japan could use photos taken on Chinese mainland and Taiwan from those days as proof of the claim.