She defeated the sitting governor of Yamagata Prefecture, Hiroshi Saitō in an upset.

She soon became a member of Yamagata Prefecture's Education Committee before running for governor in 2008.

This race was seen as an early indicator of the strength of the two main parties in Japan before the 2009 Japanese general election.

Yoshimura's rival, Governor Hiroshi Saito, was supported by both the New Komeito Party and the majority of the LDP.

[1] Aichi: Hideaki Ōmura Akita: Norihisa Satake Aomori: Sōichirō Miyashita Chiba: Toshihito Kumagai Ehime: Tokihiro Nakamura Fukui: Tatsuji Sugimoto Fukuoka: Seitaro Hattori Fukushima: Masao Uchibori Gifu: Hajime Furuta Gunma: Ichita Yamamoto Hiroshima: Hidehiko Yuzaki Hokkaidō: Naomichi Suzuki Hyōgo: Motohiko Saitō Ibaraki: Kazuhiko Ōigawa Ishikawa: Hiroshi Hase Iwate: Takuya Tasso Kagawa: Toyohito Ikeda Kagoshima: Kōichi Shiota Kanagawa: Yūji Kuroiwa Kōchi: Seiji Hamada Kumamoto: Takashi Kimura Kyoto: Takatoshi Nishiwaki Mie: Katsuyuki Ichimi Miyagi: Yoshihiro Murai Miyazaki: Shunji Kōno Nagano: Shuichi Abe Nagasaki: Kengo Oishi Nara: Makoto Yamashita Niigata: Hideyo Hanazumi Ōita: Kiichiro Satō Okayama: Ryuta Ibaragi Okinawa: Denny Tamaki Osaka: Hirofumi Yoshimura Saga: Yoshinori Yamaguchi Saitama: Motohiro Ōno Shiga: Taizō Mikazuki Shimane: Tatsuya Maruyama Shizuoka: Yasutomo Suzuki Tochigi: Tomikazu Fukuda Tokushima: Masazumi Gotoda Tokyo: Yuriko Koike Tottori: Shinji Hirai Toyama: Hachiro Nitta Wakayama: Shūhei Kishimoto Yamagata: Mieko Yoshimura Yamaguchi: Tsugumasa Muraoka Yamanashi: Kotaro Nagasaki