Tensei Akujo no Kuro Rekishi EP1 - Magical Ability is More Important Than Study Ability

Office worker Satou Konoha dies in an accident and is reborn as a character from a story she wrote as a student—The Dark History. Instead of reincarnating as the heroine as she'd hoped, she's the hated little sister, Iana. And, according to the story, she's destined to perish early on at the hands of her butler! There's only one way to survive—remember the plot of the story and avoid her fate!