Sarusuberi Danshi Koutou Gakkou!!

Haruka grew up in a destitute home. Since she couldn't get into a good high school, she decides to hide the fact that she's a woman and goes to an all-boys' high school. However, the dorm that she's living in now is full of hooligans with rotten behavior, not to mention bad grades...

(Source: Clairparfait)