乙女ゲームの悪役令嬢に転生したら裏設定でふたなりでした

I awaken to find myself in an unfamiliar room. It seems to be some kind of luxurious mansion. I take a look in the mirror, and in the reflection stands… the villainess of an otome game. It would seem I have been reincarnated as the villainess of a game I was recently engrossed with… However, while a shock indeed, that's not the biggest surprise in store for me. For between my legs… It would seem that this villainess had been packing an even bigger secret all along…!!! An isekai fantasy story about conquering all the female characters as a futanari dickgirl with a massive magnum dong! (Source: DLSite, edited)