According to the sources, this youkai girl was a guy that turned into a girl due to the culmination of lust from evil spirits and is now in a youkai brothel. So the gender bender happened offscreen.
Looks like the game can be downloaded here https://www.onlyhgames.com/ayakashi-yuukaku-satori-oni-no-seiten-kitan/
And someone translated it here: https://www.patreon.com/posts/translated-game-101548447?utm_medium=clipboard_copy&utm_source=copyLink&utm_campaign=postshare_creator&utm_content=join_link