Tokyo is with her. Photo by Kazuhiro Nogi/AFP/Getty Images.
Not only was this a big win for her (she defeated her closest opponent by over a million votes), but it's also a huge win for Tokyo, a city that doesn't have the greatest track record on women's rights.
"Hillary used the word 'glass ceiling,'" Koike said in 2008. "But in Japan, it isn't glass, it's an iron plate."
This isn't Koike's first tussle with that iron plate. She served previously as Tokyo's first female defense chief and launched a campaign in 2008 to become Japan's first woman prime minister.
When it comes to politics, the first thing on Koike's to-do list is making Tokyo better for women.
She wants to overcome the massive childcare shortages plaguing the city, and enact policies that ensure "both women and men can shine in Tokyo."
Koike drinking tea with former Prime Minister Junichiro Koizumi. Photo by Kiyoshi Ota/Getty Images.
She's also made a point of praising other female world leaders, including Hillary Clinton, Margaret Thatcher, and most recently, Tsai Ing-wen, Taiwan's newly-elected female president.
Koike is a vocal critic of North Korea and a green candidate with a focus on the environment. She served as Japan's environment minister from 2003 to 2005, where she took creative approaches to energy conservation, such as a widely adopted program encouraging male businessmen not to wear suit jackets to work (so that office air conditioners could be comfortably turned down.)
She also cosplayed once as Sally the Witch, which is just kind of awesome:
Among her biggest responsibilities as governor will be helping to shape up Tokyo's 2020 Olympic hosting duties, which are currently wrapped in multiple corruption scandals.
Like any politician, she's not without a few controversial opinions.
Most notably, she was endorsed by the Japanese Society for History Textbook Reform, an organization that seeks to revise history textbooks by downplaying Japan's involvement in war crimes and human trafficking during WWII.
In an op-ed voicing her support for textbook reform, she claimed that shifting national focus away from the antagonisms of the past would help avoid the wars of the future. It's a nice sentiment, but there's just something about George Santayana's quote, “Those who cannot remember the past are condemned to repeat it," that rings just a bit truer.
Photo by Kazuhiro Nogi/AFP/Getty Images.
When she takes office, Koike will be one of only three women serving in a gubernatorial position in Japan.
Currently, only about 12% of parliament seats in Japan are held by women. And according to the Global Gender Gap Report, the country is ranked 101 out of 145 in terms of gender equality.
That's why her victory is so important. Change doesn't happen instantly, it happens one step at a time, one election at a time, one vote at a time. When women are in politics and are elected to prominent positions of power, the world sees the benefits.
Koike with Yukari Sato and Kuniko Inoguchi, two other female lawmakers in Tokyo. Photo by Yoshikazu Tsuno/AFP/Getty Images.
Science agrees. When women are elected, gender gaps close, productivity increases, and most importantly, the world gets female role models — which leads to more women in politics and positions of power.
Now, millions of women and men in Tokyo, are living in a city that has one more female leader. She may not be perfect, and she may not solve all of Tokyo's problems, but no candidate is or could. What's important is that she's the first, and she won't be the last. Not to mention, the neat thing about barriers is they never become unbroken.