Shindemo Oshimasu!!: Jinsei Nidome no Koushaku Reijou, Kondo wa Dansou Kishi ni Natte Saioshi Konyakusha wo Osukui shimasu

Serena is a duke's daughter who is engaged to Finis, the head of the empire's pride, the Black Wolves Knights Order. Ever since she first saw his portrait, she became infatuated with him and has been fangirling over him with feverish fervor. But just when their wedding day was close, the two of them were suddenly killed by someone.

By the time she realizes it, her "second life" had already started with memories of her past life still in tact. Determined not to let Finis die this time, Serena joined the knights order so she can protect her number one bias, Finis as a knight herself!

(Source: Kodansha, translated)