Rocky Horror Show writer, New Zealander Richard O'Brien, says that he thinks of himself as 70% male and 30% female.
O'Brien delighted in shaking up the conservative sexual attitudes of the 1970s and even has a statue to his Riff Raff character in Hamilton's CBD.
His most famous creation, Dr Frank N Furter, brought the house down with the song Sweet Transvestite.
But the show's creator was ashamed about his own long-held desire to be more feminine, the BBC reports.
"I was six-and-a-half and I said to my big brother that I wanted to be the fairy princess when I grew up. The look of disdain on his face made me pull down the shutters. I knew that I should never ever say that out loud again."
For 50 years, O'Brien repressed the feeling. But "you can't just put the lid on things and pretend that they don't exist", he says.
So a decade ago, he started taking the female hormone oestrogen - and is happy with the results.
"It takes the edge off the masculine, testosterone-driven side of me and I like that very much. I think I've become a nicer person in some ways, slightly softer. For the first time in my life, I've started to put on a little bit of weight, which I like."
He has also developed small breasts. But O'Brien is not intending to go further and have sex reassignment surgery.
"I don't want to pretend to be something that I'm not. Anton Rodgers, the actor, said 'you're the third sex'. And I thought that's quite nice. I quite like that position.
"It's my belief that we are on a continuum between male and female. There are people who are hardwired male and there are people who are hardwired female, but most of us are on that continuum and I believe myself probably to be about 70% male, 30% female."
In the context of moves that Britain is making to gradually remove the requirements for people to declare whether they're a man or a woman - Australia and Spain are doing away with the need to tick a box on a passport stating if the bearer is male or female - O'Brien says: "I tick the M.
"But I would quite like to have Other to tick."