Shizuku Mihara, who attends Ozashiki Gakuen High School, has a strange encounter at her grandpa's house during the summer vacation before her exam. Shizuku wanted to go to the literature department, but due to her family lineage, she enrolled in the horse racing department of the parlor school. Shizuku, whose grades haven't improved much, looks up to Primrose and Shiho Dome, who are the two top girls in the class. The story of high school girls who strive to win the ``BKCC Kotori Ogami Festival (GI)'' race, which decides the top of officially sanctioned school horse racing in Japan.