"I'm breaking off my engagement to you."

Suddenly hearing those words while attending a resplendent party shocks Aileen Lauren Dautriche into remembering her previous life, and she comes to understand her situation. She is in the world of the otome game "Regalia of Saints, Demons, and Maidens" as the villainess, Aileen, who gets in the way of the main character's romance! According to memories from her previous life, Aileen's only route in the game is a one of doom that leads to a messy death. But if she makes the last boss, the demon king Claude, fall for her, then she might be able to avoid doom after all! Thinking that, she declares to the beautiful demon king:

"I would like you to marry me!"

Aileen's journey to turn things around and find happiness is about to begin!

[Source: Crunchyroll]