Unlike the modern nation-state system, which demarcates independent states by clear borders, the Sino-centric world did not necessarily maintain clear boundaries between countries and regions.

Yezochi, inhabited by Ainu people or the islands of Hokkaido, Sakhalin and Kuril Archipelago, and the Ryukyu Islands were, thus, frontiers without clear borders between Japan and two countries: Russia and China. However, these ambiguous zones became problematic when Japan was pressured to join the modern nation-state system. Hence, during the late nineteenth century, the Meiji government attempted to clarify boundaries in the frontiers of both North and South.

 In 1872, in an attempt to show that the Ryukyu Islands had been the formal territory of Japan, the Japanese government designated the archipelago the Ryukyu-han, which implied that the Tokugawa Shogunate regarded Ryukyu Kingdom as one of the Japanese clans. Yet the government initially did not deny the Kingdom had been a tributary country of China. Rather, the government claimed that Ryukyu Kingdom was not an independent country, but belonged to two countries: Japan and China. In other words, Japan still partly dealt with the diplomatic issues with China by employing the language of Sino-centrism (Kokaze 2001, 5-7).

The Japanese government began to negotiate the southern border in terms of modern nationalism after troops were sent to Taiwan in revenge for the murder of some Miyako fishermen, who accidentally drifted to Taiwan in 1874. Okubo Toshimichi, who was determined to establish diplomatic relations with China under the nationalistic discourse, took responsibility for the sending of Japanese troops to Taiwan. While the Japanese government justified the sending of the troops by claiming that the Ryukyuans who were killed by the Taiwanese aborigines were Japanese nationals, the Qing government demanded Japan removed the troops. In the end, in October 1875, they reached an agreement that the Qing government pay compensation in exchange for the removal of the Japanese troops from Taiwan. This did not automatically mean that the Ryukyu Islands would be exclusively owned by the Japanese nation. But in reaching the agreement, the Qing government implicitly admitted that the Ryukyu Kingdom had been under the Japanese control as well as being a tributary country of China and that the Japanese government was thus entitled to demand compensation from the Qing government on behalf of the Miyako fishermen, who were Ryukyuans (Kokaze 2001, 12-18). 

Japan recognized that China had not yet given up its rights in the Ryukyu Islands. In 1875, the Japanese government officially forbade the Kingdom to send tributes to China. Shuri Castle, the seat of the Ryukyu King was taken over by the Japanese in 1879.

However, the Japanese government did not intend this to develop into a serious conflict. In an attempt tp settle the dispute, the Japanese government immediately began to renegotiate with the Qing government, through the intermediation of Ulysses Simpson Grant, who had been the President of the United States between 1869 and 1877. As a result of the negotiations, in 1880 Japan agreed to divide the Ryukyu Islands, and to cede the Miyako and Yaeyama Archipelagos to China. But due to great opposition to this proposal within China, this agreement was never officially ratified and was finally abandoned.

The definition of the boundary was not simply a matter of diplomatic relations. Civilians also actively participated in drawing the national border in the southern frontier. This section explores two pioneer Japanese: Tashiro Antei and Nakagawa Toranosuke.  Interestingly, both pioneers, who first claimed the significance of Yaeyama Islands, migrated to Taiwan soon after the Japanese victory over the Sino-Japanese War (1894-1895).