Any girl can Feminizes Harry Ginny was just my example
Ginny sick of Harry ignorin her captures him the summer before 5th year. She strips him of his magic. She then forces him to wear girls clothes and eat salad in place of as must lose weight. Ginny conditions him into liking boys and she slowly break him. He is forced to read books aimed at girls. She gives him a new girly name and He is kept at home (no more Hogwarts) where he is trained in the skills he will need to be a proper housewife one day.
Harry must resist in the beginning before he is slowly broken and made into a submissive girl. By the end he has no trace of his former self left in him and is planning his wedding day. Must be drawn out and contain Ginny brainwashing him into his new role.
Can include BDSM type Punishment for non feminine behavior and brainwashing.
How all this is done is up to you as long as it’s this premise. In fact anyone can do it to Harry. Ginny, Molly, Hermione any female character.