Manga Like Watashi ga Shinde Manzoku desu ka? Utomareta Reijou no Shi to, Nokosareta Hitobito no Hametsu Nitsuite

Countess Rorona Ryus died in an accident. The news came the day after her fiancé, the crown prince, called off their engagement. Rorona was accused of mistreating her sister, a crime she did not commit, but she accepted the blame without rebuttal. She was found dead in an overturned carriage on a suburban street, her face tragically smashed in. When Rorona's sister learned of her death, she was delighted. "The prince is now mine," she said. The prince laughed, "I wish she had died sooner." But they had no idea what Rorona's death would bring. (Source: Regina Bunko, translated)