Ohitorisama ni wa Naremashita node.: Kon'yakusha Houchi-chuu!

Noble young lady Nicole has had her heart broken more times than she can count. Her fiancé Keios is so devoted to Princess Caroline, his childhood friend and the unrivalled belle of their aristocratic academy, that he seems to forget Nicole even exists. But no longer. Tired of waiting around and conforming to Keios’ needs, Nicole makes a most liberating decision: I’ll give up on love and go it alone. Her arranged marriage may be unavoidable, but that doesn’t mean she can’t enjoy her own life, right? Emboldened and excited, Nicole begins to shine as she never had before—so brightly, in fact, that even the clueless Keios can’t help but notice…

Source: Kodansha Comics

https://www.cmoa.jp/title/293676/