Okubyou na Hakushaku Reijou wa Momegoto wo Nozomanai

Amelia is a plain girl who is Sophie's fan and follower. One day, she sees Marion, Sophie's fiance, with Rozetta, another girl.
"I wonder if His Highness will look at me more if I earn Rozetta's ire..."
To prevent Sophie from becoming the antagonist, Amelia begins to coach Sophie in love. However, this attracts the attention of Sophie's tsundere brother?!