Code Geass: Yoshiko of the Insurrection (コードギアス 反逆の善 子)
10 parts Complete MatureSchool Idols: A popular type of idols that originated from Japan. It was so popular, that the most popular group was made the ruler of all school idols. The popularity had reach its peak to the point that it influences the government and its laws.
After μ's has won Love Live! and has urged the emperor to give his empire to theirs. The royal family then disappeared, spared for a few members who would guide μ's in leading the empire. Honoka zi Kosaka wanted the group to remain popular, but was unable to do so. Umi la Sonoda and Eli el Ayase had given laws that eventually led to the oppression of other school idol groups.
This led to groups losing popularity, with each group either getting subjugated by the empire, now called the Sacred μ's Empire, or fighting against it. School Idols tried to gain popularity by either doing it the traditional way, by songs, dances and performances, or by doing things that is pretty much obscene. Those who fight the empire rushed to get the Knightmare Frames left by the former empire, while the Sacred μ's Empire started deploying and improving them. Fans of their respective school idols were deployed to fight alongside their favourites, often sacrificing themselves for them.
While at Tokyo, Yoshiko had came into contact with the chairwoman of Nijigasaki High School, who granted her the power of Geass. Will she succeed and change the world of school idols? Or would she fail and let the world of schools be as it is now? No one knows.
Cover sauce: https://twitter.com/barkhorn0331/status/1505449567655178249?s=21