Kimi To Himitsu No Hanazono

From Operation Boredom:
Having being raised by her family as a boy, Natsu simply wants to be a pretty girl. To make this wish into a reality, she moves to an all-girls school. Her roommate, Huzio, is a pretty girl – one that Natsu always wished to be. However, Huzio is actually a boy who is secretly practicing acting like a girl to take over the family business of kabuki. Quickly, Natsu and Huzio become good friends and decide to share their secret.