She currently holds both Japanese and American citizenship, but that will soon end. Japanese citizens who hold dual citizenship must choose either their Japanese or their other nationality when they turn 22 years old as the country does not allow dual citizenship, according to Quartz. Osaka, who is 21, turns 22 on October 16, 2019.
According to the Wall Street Journal, Osaka’s father decided when she was young that she would represent Japan athletically because the family has “always felt Japanese.” The fact that Japan’s tennis association has always been supportive of Osaka’s athletic career has also played a part in why she represents Japan and not America. Osaka was largely overlooked by American tennis associations until she played in the Australian Open in 2016. When the Americans came to poach his daughter to become the next American tennis star, Leonard Francois decided she would continue to represent Japan because they had always been supportive of Naomi, not just when she began to get famous, according to Nikkan Sports.
As Osaka has since enjoyed titles such as being the first world #1 player from Asia after defeating Petra Kvitova at the Australian Open, some speculate that when she turns 22, Osaka will ultimately choose her American nationality. One such person is Michio Ushioda, a journalist for Mainichi newspaper in Japan. He tweeted that he believes Osaka will decide to give up her Japanese nationality, that the loss for Japan will be great, and speculates, perhaps in jest, that the Japanese government will collapse as a result.