The story takes place at Otonogizaka Academy in Tokyo. The economic downturn, aging population and other social problems have made it difficult for the school to recruit students. Unable to find students, the school had to close down. At this time, nine girls stood up. These girls who have deep feelings for the school decided to make efforts to protect the school from being closed down. The lively and energetic Takasaka Honoka (voiced by Nitta Megumi), the gentle Sonoda Umi (voiced by Mimori Suzuko), the gentle and brave Minami Kotori (voiced by Uchida Aya), the smart and clever mixed-race girl Ayase Eri (voiced by Nanjo Aino), the self-willed student council president Tojo Nozomi (voiced by Kusuda Aiina), the tsundere young lady Nishikino Maki (voiced by Hori Eriko), the athletic girl Hoshizora Rin (voiced by Iida Riho), the unknown Koizumi Hanayo (voiced by Kubo Yurika), the OTAKU otaku Nico Yazawa (voiced by Tokui Aozora), these brave girls formed an idol group and vowed to make absolute efforts to protect the school from being closed.