Democratic Party lawmaker Renho has found herself in the unenviable position of having to defend her Japaneseness. On Tuesday it was finally confirmed that the runaway favorite to lead Japan's top opposition party still has Taiwanese citizenship through her father, a national of that country.

Renho has a Japanese mother but did not gain Japanese citizenship until 1985, when she was 17 and a change in the Nationality Law allowed children born of a Japanese mother and foreign father to be registered as citizens. Before that, citizenship for those with a foreign parent was determined by the father's nationality alone.

The 1985 change in the law also required all dual citizens to make a "declaration of choice" renouncing either their Japanese or any other citizenship they may have before reaching the age of 22.