Tensei Reijou wa Goinkyo Seikatsu! Outaishidenka to no Konyaku wa Goenryosasete Itadakitaku

I was supposed to be reincarnated as a mob, but when I realized it, I was the daughter of a duke who was confirmed as a "saint"?!
I'm so sorry to have to do that! Brush up on the "Stealth" skill you got from the Nyanko God -- Aim for a relaxed retirement life! I was going to do that, but the Crown Prince, who is known as the "Noble Prince of Absolute Ice", approached me with a passionate proposal! Please don't look at those melting eyes?!