"The defective daughter of the Marquis family, or in other words, the failure of the Marquis household—my older sister is excellent at everything, and compared to her, I, the defective one, am told I can do nothing. But the truth is... It is..."

I am the failed daughter of a marquis family, a lady spoken of as a "dud." Compared to my older sister, who excels at anything she does and possesses beautiful looks, I am said to have a plain face. In terms of intellect too, my sister is superior and I am called stupid—but that's not actually true. This is a story of a younger sister, who has been oppressed by her parents and looked down upon by her older sister, grasping happiness through her own wisdom.