The ugly daughter of the prestigious noble family, the Bellux, Eira had heard the "whisper" of everyone's vicious thoughts in her whole life. Being unable to trust anyone, her only ally was her family. She didn't want to hurt them, she didn't want to bring them down. That's why she determined to become a Lady, enough just to not shame her family, even though it's impossible. Then that night, at her 13th birthday party, the Emperor announced her as the future Empress...

"But I don't want to? I don't want to become the villainess whose only ending is to be killed by the heroine! Oh, that's right! Let's help the heroine and the prince get happy together, so he'll annul the engagement peacefully. I promise I won't mess with the monsters, so please don't kill me!"

Thus, the "Boar Princess" will help the heroine and the prince to fall in love with each other, while retorting rude thoughts and saving the world.