In its editorial on Sep 9, the Japan News says the opposition Democratic Party leader's lack of awareness about dual nationality is problematic.
It is nothing but a sorry state of affairs that a Diet member has failed to correctly understand her own nationality.
Ms Renho, newly elected leader of Japan's opposition Democratic Party (DP), admitted at a press conference on Tuesday (Sept 13) that she retains Taiwan citizenship. Taiwan is her father's birthplace.
Until that day, Ms Renho had explained that she had renounced her Taiwan citizenship when she obtained Japanese citizenship in January 1985.
After she filed her candidacy for the DP leadership election, it was pointed out that she might have dual citizenship. She then reportedly had the Taiwan side check whether she still possessed Taiwan citizenship, and it turned out that she did.
It has transpired that Ms Renho let this abnormal state of affairs go uncorrected for more than 30 years.
"I have caused various sorts of confusion because of my inaccurate memory," she said in apology.
Ms Renho said she would retake the procedures to renounce her Taiwan citizenship. This response, however, came too late.
The Japanese government does not allow dual nationality. The Nationality Law stipulates that a Japanese national with dual nationality must choose one, in principle, before they reach 22 years of age.
Although there is no provision excluding people with a foreign nationality from becoming a Diet member, they are prohibited from being appointed as diplomatic officials.
It is out of the question for a legislator - who is supposed to serve the interests of the nation, including in foreign affairs and national security - to leave their own nationality obscure.
Ms Renho said that at 17 she undertook procedures to renounce her Taiwan citizenship at Taiwan's de facto embassy, the Taipei Economic and Cultural Representative Office in Japan.
She failed to confirm that the procedures were completed.
Ms Renho, who also failed to confirm this when she ran in the 2004 House of Councillors election, has such little understanding of what it means to be a politician that her quality as one will be put into question.
Although Taiwan is friendly towards Japan, it is in conflict with the Japanese standpoint regarding some issues, for instance, its ownership claims on the Senkaku Islands. If Ms Renho retains her Taiwan citizenship, she could become the target of undesirable suspicions regarding her relations with Taiwan.
That Ms Renho's explanations have been inconsistent is not to be overlooked.
Initially, she asserted that she "had renounced Taiwan citizenship".
She even showed displeasure, saying: "It is very sad that the rumours are making their rounds."
Later, however, the age she said she took the procedures changed from 18 to 17.
An interview carried in a magazine about 20 years ago came to light in which she referred to possessing Taiwan citizenship.
Some have also pointed out that the description she made on an official list of the details of electoral candidates for the upper house election ran counter to the Public Offices Election Law.
Her description said she "became naturalised from Taiwan citizenship".
Saying that "there is no illegality", Ms Renho emphasised that she would not withdraw her candidacy in the DP leadership election.
She must further clarify all the facts and be accountable.
DP leader Katsuya Okada said: "It would be extremely unsound if the recent commotion partly stems from such a way of thinking as, it is inappropriate because her father is from Taiwan."
That such a twisted interpretation can be heard within the party, whereby criticism towards Ms Renho could be taken as a form of racial discrimination, is hard to understand.
What is being considered as problematic lies absolutely with the fact that Ms Renho failed to take necessary procedures in accordance with the law.
The Japan News is a member of The Straits Times' media partner Asia News Network, an alliance of 21 newspapers.