About Mazie Hirono
Mazie Hirono was born in Japan and went on to serve in the US Senate representing HI. Mazie Hirono's career in Congress began in 2013, during the modern Congress, and has continued into the current session — 13 years and counting. As a Democrat, Mazie sat in a chamber where most colleagues were born in the United States; naturalized citizens remain a small minority of Congress in every era.
Japan reserves the ballot for its own citizens: non-native-born residents cannot vote in any election there, no matter how long they have lived in the country. In practical terms: Only Japanese citizens can vote. Dual citizenship is prohibited. Non-citizens have no voting rights at any level. That produces a striking asymmetry with the United States, which not only naturalized this member but then elected them to help write federal law. A naturalized American who returned to Japan would have no such political voice there.
Japan has sent 2 naturalized citizens to Congress in total, of whom 1 also served as Democrat like Mazie. Across the full history of the US Congress, Japan ranks 14th of 38 tracked birth countries, accounting for 2 naturalized-citizen lawmakers.
Why does Japan's own voting regime matter on an American member's profile? Because it frames a question the US Congress itself wrestles with whenever immigration and citizenship come up: which countries extend the same democratic trust to people who arrived later that the United States extended to Mazie? In Japan's case, the answer today is no — a naturalized American returning there would hold no ballot at all.