Imaginative geography was a tool of the colonized as much as it was a tool of empire. In 1928, Cai found the Japanese Empire at a point that was both fraught and fortuitous. In 1925, the Imperial Diet passed universal suffrage for male residents of the metropole. Cai, who had been advocating for an end to legal discrimination against Taiwan for nearly a decade, saw in universal male suffrage a chance to change the electoral math that kept Taiwanese Chinese activists’ complaints far from the minds of the Diet’s members. With the first post-suffrage act election for the House of Representatives approaching, Cai appealed to the newly-enfranchised citizens of the Japanese metropole to demand self rule for Taiwan.

Nihon honkokumin ni atau sought to change the everyday practices of spatial thought that perpetuated discrimination against Taiwan. In particular, Cai wanted to correct the assumptions that led Japanese people to treat Taiwan, and Taiwanese people, as wholly different from themselves. The Japanese public had to stop thinking of rights as primarily determined by place and instead think of rights as inherent to all people of the empire. Cai penned this manifesto, Nihon honkokumin ni atau, to demand that Japanese people account for, value, and protect the specific character of Taiwan and Taiwanese identity, while at the same time recognizing the equality of Taiwan and Taiwanese people among regions and ethnic groups in the Japanese Empire.

“I am one of 3,800,000 Taiwanese people. Here, I would like to address the 60,000,000 people of the Japanese metropole from my heart.”

From its very title, Nihon honkokumin ni atau revolves around the relationship of place to identity and of place to political rights. Cai began by addressing the manifesto to “the people of the Japanese metropole.” The standard term for Japanese people at this time would have been “people of the inner territory,” or naichijin. This term applied to Japanese people living in Taiwan as well as to Japanese people living in the main islands. Yet Cai eschewed this ethno-geographic marker of power. Instead, he chose a term that identified his audience as those people who lived in the metropole—whether or not they were Japanese—and excluded Japanese people in Taiwan. Throughout the manifesto, Cai bypassed the standard ethnic hierarchy of empire, which put naichijin above all other ethnic groups, no matter their place of residence. He defined himself in a way that emphasized the multiplicity of identity and his fundamental equality with other subjects of the Japanese state: as a fellow countryman (dōhō), a citizen of Japan (Nihon kokumin), and a person of Taiwan (Taiwanjin). His most common form of address was “gentlemen!” (shokun!), and his most frequent subject was “we” (ware ware), by which he meant people of Chinese ancestry living in Taiwan.

Cai used this new terminology to show that people in the metropole actually shared a history with people in Taiwan. For Cai, what divided the people of the Japanese Empire was not ethnicity or race. It was political power. Despite the ubiquity of designations like “inner territory person” and “person of Taiwan,” Cai argued that prior to the passage of the Universal Suffrage Act the empire had been divided into “rulers” (shihaisha) and “the ruled” (hishihaisha). Japanese people were as much a part of “the ruled” as Taiwanese people. A person of limited means who lived in Tokyo could no more vote for their Diet representative than a Taiwanese Chinese person in Tainan.

“If conditions were the same as they had always been, I would have unavoidably chosen the gold of silence over the silver of speaking. Happily [however], an opportunity has arrived. In the metropole, the system of universal suffrage has now been established. You who had no prestige have suddenly gone from the position of the ruled to stand in the position of our rulers. It is now the era in which you who were our comrades as members of the ruled are on the verge of conducting yourselves as our rulers.”

But, he continued, universal male suffrage fundamentally altered the distribution of political power.  Now people who resided in the metropole, or “inner territory,” could vote. People who lived in the colonies could not. People in the metropole could decide whether to pressure their representatives to repeal the laws that granted the Governments General nearly dictatorial authority over life in Korea and Taiwan. The people who actually lived in these regions could not.

Cai called on the people of the inner territory to draw on their past experience as members of “the ruled” and take a stand against the unequal treatment of Taiwanese Chinese residents of Taiwan. Newly empowered voters could recognize the people of Taiwan as “fellow countrymen.” Or, they could do nothing. They could allow a stark spatial order of “inner territory” and “colony” to come into being.