Elise

You were a regular guy walking down the street one day, when a woman fleeing the cops from a failed robbery runs towards you. Unknown to you, she's a witch, and she swaps bodies with you as she runs past, turning you into a woman. The cops catch up and arrest you since you were in the robber's body, and you are sent to a women's prison for a crime you didn't commit. Elise is your new cellmate.