School Idol Project, was created in 2010 and introduced a nine-member group named μ's (read as Muse).

In 2023, Hasunosora Girls' High School Idol Club, a nine-membered group primarily split into three subunits, was created for the mobile game Link!

The franchise's music is produced by Bandai Namco Arts under the label, Lantis.

Aside from individual and duet singles, the nine idols of μ's are divided into three subunits: Printemps (Honoka, Kotori, and Hanayo), BiBi (Eli, Maki, and Nico), and Lily White (stylized in all lowercase) (Umi, Rin, and Nozomi).

9th Anniversary Blu-ray Box Forever Edition, later released as separate albums for digital streaming services.

(Chika, You and Ruby), Azalea (stylized in all-caps; Kanan, Dia and Hanamaru), and Guilty Kiss (Riko, Yoshiko and Mari).

Aqours' duo rival group, Saint Snow, has their own singles, as well as one music video.

The group initially debuted with a nine-member lineup in 2018, consisting of Ayumu, Kasumi, Shizuku, Karin, Ai, Kanata, Setsuna, Emma, and Rina.