Majisuka Gakuen Season 3

The story takes place in Prison HOPE, year 20xx. With the reform of Juvenile Law, private juvenile prisons were born. Dangerous delinquent young girls, abandoned by society, school, and even their families, are gathered in a place where the detention period is unlimited. The battle ring, where only the fittest survived, is also called Majisuka Prison.
(Source: DramaWiki)