In Tokyo's Chiyoda-ku is the traditional school Otonokizaka High. Second-year student Kosaka Honoka discovers the school will be closed in three years. In order to avoid being closed, the school must increase its number of prospective students.

Honoka and friends form a school idol group to entice more students to attend. When it is pointed out that their group could have the opposite of their desired effect, Honoka becomes dispirited.

Honoka's group idol name is "μ's" and the group debuts their first song. Their popularity grows at school, and they have their first concert.

μ’s complete their first concert in an empty auditorium. In an attempt to get a massive crowd for their next performance, Honoka tries to recruit Hanayo.

μ’s is now at 6 members with the addition of Hanayo, Rin, and Maki. The group attempts to make their idol group into a proper school club. However, they are informed another idol club exists, and must negotiate with them.

μ’s have officially become a school club! The student council vice president asks Honoka why she is the leader when she does not have any responsibilities in the group. So, the group sings and dances to determine their new leader!