Now some otome games are playable on Vita3k, I've not tested Collar x Malice but you can try.
here my guide and tested games: http://www.anime-sharing.com/forum/otome-corner-126/otome-games-playstation-vita-using-emulator-1080268/
Vita3k don't works yet, but...
You can play Collar X Malice, Collar X Malice -Unlimited-, Code Realize ~Guardian of Rebirth~ and Code Realize ~Future Blessings~ (and other games) in Yuzu (Nintendo Switch Emulator), see how to play in yuzu here...
Yes, you can try to play visual novels on yuzu, I have only played english otome games and a game called Buried Stars.
Games may work different, with different settings. Ryujinx is another switch emulator.
Yuzu guide...