Volume 1:
The protagonist, an ordinary old female office worker, ends up being reincarnated into the world of an R18 Otome game as the villainess. While she may be one of the prince's fiancée candidates, when the prince falls in love with the game's heroine, she is a side character destined to be executed or at least that's how the story was supposed to go. For some reason, her betrothal to the prince was successful.

The protagonist is perplexed by the turn of events which is different from the game's story that she knows.
On top of that, the prince's aide has come along and what's that? He's here to teach her (in the) bed manners, and foreplay technique because the prince dislikes virgins?

Being a virgin in both her previous and post-reincarnation lives. In order to avoid being executed, the protagonist ends up accepting lessons from the sadistic instructor. The tale of a woman who undergoes sweet intense pleasure discipline at the hands of a mean sadist.

There is a TL and R18 version.

Official Translations:
English

Volume 2:
Sadistic Disciplinary Instructor x Villainess

The protagonist, an ordinary old female office worker, ends up being reincarnated into the world of an R18 Otome game... as the villainess!

However, an unexpected turn of events, different from the game's story, sees her being taught in-the-bed manners and foreplay technique by the prince's sadistic aide!?

To avoid being executed, the protagonist accepts those lessons and undergoes sweet intense pleasure discipline at the hands of a mean sadist.

Her in-the-bed manners should now be perfect... and yet!?
What the...! Starting from scratch!?

The mean and sadistic instructor's lessons on in-the-bed manners become even more extreme!!
He relentlessly teases her clit, and launches a barrage of humiliating sexual situations upon her!?

Official Translations:
English

Volume 3