Becoming Her (смешанная)

When he wakes up, the world is peaceful. Birds are singing in the forest, the sky is clear and blue and the bright morning sun streaming in through the windows makes the bed hangings look like they are glowing as they sway gently in the soft breeze. For once, Harry’s night had been blessedly free of nightmares, and he is in high spirits as he gets dressed in the girls' uniform- wait, what?!
Or: One perfectly normal day, Harry wakes up only to find the world titled on its head, everyone he knows and everyone he doesn't know convinced he is a she. Everyone? Not quite. A certain Potions Master is not affected by that evil curse and, luckily for Harry, willing to help him end this nightmare.
As a spoiler: the curse will be gone at the end of this story.