Dogeza Shoujo no Gekokujou: Ikenie Revenge Game

In a mysterious school, there is a class where students with the lowest grades are sent, named the "isolated class." Akari, an ordinary female student, falls into the "isolated class" due to her friend's betrayal, where she is exposed to irrational senseless violence! However, she stands up to the members who dominate the class with an unyielding heart. At the same time, Akari joins forces with Yuuto, another student who has fallen into the segregated class, and vows to climb out of this mess...

(Source: Bunkasha, translated)