After being reborn as the villainess Ekaterina from an Otome game, Yukimura Rina vows to alter her fate and that of her kingdom. With a deep affection for her brother, Alexei, she sets out to navigate the intricate game events using her wit and historical knowledge. As time passes, her brother's sibling affections take a peculiar turn, leading to a mix of brotherly and sisterly love. Despite her efforts to avoid the game's tragic outcomes involving the Heroine and Prince, the narrative twists in unexpected ways. Determined to protect her brother and rewrite her story, Ekaterina faces a world where the game's rules no longer apply, propelling her on a mission to ensure their happiness.