8-dome no Jinsei, Kirawareteita Hazu no Outaishi Denka no Dekiai Route ni Hamarimashita: Okazari Sokuhi nanode Douzo Okamainaku

In order to broker a peace with an enemy nation, Princess Fiona is sent off to be the concubine of their crown prince, Othniel. Her new husband treats her as little more than a political hostage, and she is soon executed on false charges, or poisoned, or worse... Yet no matter how she meets her end, she always goes back to the same day and restarts her life from there. Determined to survive her eighth life no matter what, Fiona vows to give up her hopes of love and be content with life as an ornamental bride, but now, after seven straight lives of hating her on sight, Othniel seems to be madly in love... "What's going on?! I was supposed to just be here for decoration!" (Source: MangaPlaza)