Kurihara, Mari

She wears the standard female school uniform with dark tights.

During her incarceration, she wears an undersized female prison uniform consisting of striped short tank top and matching short striped trousers.

Mari is a proud and dignified student who exerts a sense of authority about her that lends to her popularity. Mari prefers the company of crows to people outside of her subordinates and closest friends that are senior members in the Underground Student Council, and she can control them.

Though Mari's strained relationship with her perverted father results in her misandry treatment of the boys, she adapts to be able to socialize with the boys and empathize with them.

Mari is a genuinely kind person deep down, as shown when she helped a younger Meiko Shiraki to become more confident and prevented her Kate Takenomiya for bullying her in middle school.

Mari is well known for her intelligence, athletic ability, leadership abilities and all-round talent both in her middle and high school years. She is a calm and controlled character who displays intelligence and cunning throughout the series. Mari is also very close to Chiyo Kurihara , whom she shared her childhood with even as she grew estranged from their father.

(Source: Prison School Wiki)