Seijo no Imouto no Shirinugui wo Ousetsukatta, Tada no Jijo de Gozaimasu

Dorothea, the daughter of a viscount, has spent her entire life overshadowed by her younger sister. While her sibling is blessed with striking beauty and revered under the prestigious title of "Saint," she is also deeply selfish. In stark contrast, Dorothea is treated as nothing more than an ordinary girl, enduring constant scorn and disdain from both her own family and the society around her. The fragile peace shatters when the so-called Saint commits an unforgivable act of arrogance. She openly insults the princess of an allied nation, cruelly comparing her to an animal. This reckless provocation quickly spirals into a severe international incident, threatening diplomatic relations between the two countries. The offended nation is Rezanard, a realm inhabited by beast-men, making the slight all the more inflammatory. With no one else willing to take responsibility for the disaster, Dorothea steps forward to clean up her sister's mess. She embarks on a solitary journey to Rezanard, intending to offer a formal apology on behalf of the Saint. However, what awaits the unassuming noblewoman in the beast-man territory may prove to be far more transformative than a simple diplomatic mission.