Sukeban Deka

Main characters in both animes are tomboyish schoolgirls fighting with evil and injustice in schools they attend to. While their goals and motivations differ, these two characters also have in common one more thing, which is the usage of original weapons during many action scenes present in both shows (yo-yo in Sukeban Deka and clothes in Kill la Kill). In both animes the main character is a tomboyish schoolgirl fighting with evil and injustice in the school she attends to. While Saki and Ryouko  

Badass girls getting involved in the underworld. Lots of delinquency going on. 

Both of these 2 episode OVAs feature high school students that get roped in with the police to become spies. They're very similar, although in Sukeban Deka she does her thing in and around her school, while in High School Agent he travels to the task in-between his school obligations. 

Both have a MC that's been with the wrong crowd. Now they frequent a high school and must wipe the scum and problems plaguing the school. Mature themes are in both such as rape, extortion, and attempted homicide (actual mass-homicides in Sukeban Deka).