Former Defense Minister Yuriko Koike on Wednesday announced her intention to run in the Tokyo gubernatorial election slated for next month, an apparent act of defiance against the ruling Liberal Democratic Party's Tokyo chapter.

If elected, Koike would be the first female leader to head the Japanese capital. But given a lack of support from within the party and access to its campaign mechanisms, her chances of being elected remain unclear.

"As the (central) government pushes for a society where 'women can shine,' I think a female governor of Tokyo would be the perfect embodiment of that idea," the 63-year-old Koike said at a news conference.