Help me please.

I have been trying to find this manga I started reading a while back but I cant remember the name of it. It is about a witch who, after her mother dies, goes to a all girls school. Everything starts off well but it turns out that she is actually a he!! He tells them that his mom has raised him as a girl because all witches are born boys and when they reach a certain age the either change into girls or they loose their powers and stay boys. I didn't get far and I want to read more. If anyone knows this mangas name either English or Japanese please post it here.

Help me please.