If you don’t remain pure, you’ll be cursed…?!

I opened my eyes underwater and saw splendid, historical palace-style buildings.
There’s no doubt—I’ve possessed someone inside a story!
And since it’s the genre I love, I know all the rules very well!

But wait… I thought I had fallen into an R-rated fantasy,
yet if you ★do that★… you get cursed?!

In this ridiculous situation,
I’m supposed to make the sub male lead’s love come true?!
Will I be able to succeed in this mission...?