Raws https://rawkuma.com/manga/higeki-no-heroine-buru-imouto-no-sei-de-konyaku-hakishita-no-desu-ga-naze-ka-seigikan-no-tsuyoi-outaishi-ni-karamareru-you-ni-narimashita/ Chapter 13
I Abandoned My Engagement Because Of My Tragic Sister, But For Some Reason I Became Entangled With A Prince Who Has A Strong Sense Of Justice.