Tensei Seijo Wa Oshi Katsu Ga Shitai! Shiitagerare Reijo Desu Ga Oshi No Ojisama Kara Dekiaisareteimasu!?

Due to an accident, the main character was reincarnated as Duchess Elysia, but because of her black hair and black eyes, she was despised as the “daughter of evil”. One day, she meets the crown prince Reichelt who she decides to stan in this life. Though she is the saint, if she uses her stanning as a ways to motivate herself and it doesn't get found out, then there's no problem!

She is so devoted to stanning him that she doesn't even realize that she's being doted on by her fave?!

A very sweet love story!