OK, here are two ideas set in the Harry Potter universe I'd like to play out, that include various amounts of male to female transformations.
The accident MtF x F
My character is a student at Hogwards who always was a bit curious at the idea of what it's like to live as a girl. One day a magical accident lets him live the dream out, including a hot moment with his best lesbian friend...
Best buds MtF x M and/or MtF.
Our characters are two boys a bit down on their luck with girls. One day my character proposes they take turns at turning into girls so they can have a date for the summer.
Sex ensues, both hetero and lesbian...
If anyone is interested, just PM me!