Moonlight Garden(2004)

Gekkou Teien

Yuuki is a girl who lies about her gender to enroll in the theater department of Getsuryou academy, an all boys’ school where all the students are required to stay in the dorm. While hiding the fact that she’s a girl, every day, she tries hard to study acting, the subject that she loves so much. One day, an upperclassman, Riku, found out her secret, causing Yuuki to be very worried, but she gradually got attracted to him. At the same time, she came to know the real reason why she was brought up as a boy…

(Source: Aerandria)