Japanese women are calling for a ban on sex with any man who voted for Yoichi Masuzoe, Tokyo's controversial new governor.
Masuzoe once claimed that women are incapable of holding positions of power because their periods make them irrational. He also described female Japanese politicians as "middle-aged hags" .
The group - called "the association of women who will not have sex with men who vote for Masuzoe" - launched last week and has gained more than 3,000 followers on Twitter.
The group says on its Twitter profile: "We have stood up to prevent Mr Masuzoe, who makes such insulting remarks against women [from being elected]. We won't have sex with men who will vote for Mr Masuzoe."
The 65-year-old became a politician in 2001, but has failed to shake off controversial sexist comments he made in 1989. In a men's magazine interview, he said that women should not hold positions at the highest level of government because their menstrual cycle makes them irrational.
"Women are not normal when they are having a period. You can't possibly let them make critical decisions about the country [during their period] such as whether or not to go to war."
In the same year, during the so-called "Madonna Boom", when a number of women became elected officials in Japan, Masuzoe stated: "This is an exceptional period in history, that's why even women are able to come out of the woodwork. But those who have been elected are all a bunch of old middle-aged hags."
Another anti-Masuzoe website has attracted 75,000 hits a day and 2,800 people have signed its petition. The politician is also unpopular for his comments on raising older Japanese people's rate of taxation.
In an interview in 2005 Masuzoe said: "The rate of consumption tax should be over 10%. Half of Japan's savings is held by old men and women. Those guys have money. If the rate of consumption tax is raised then we can extract money from old people."
Despite the campaigns Masuzoe, a former health minister and front runner during the election campaign, has been declared the new governor of Tokyo, Al Jazeera reported.
Japanese politics is dominated by men and Masuzoe is said to be a symbol of the country's gender gap. All 16 candidates in the election were men, many in their sixties or older. Prime Minister Shinzo Abe's 19-strong cabinet contains only two women.
The election was seen as a test of Japanese voters' attitude to the issue of nuclear power in the wake of the Fukushima disaster.
Masuzoe, who led a pro-nuclear power campaign, beat his nearest rival, Moriyoshi Hosokawa, a former prime minister who stood on an anti-nuclear platform. Because of his support of nuclear power as an energy source, Masuzoe's election is expected to spur efforts to restart the country's idle nuclear reactors.