Akuyaku Reijou, Brother Complex ni Job Change Shimasu

A systems engineer in her twenties, overwhelmed by work, finds solace in an otome game featuring a beloved side character—her favorite being the villainess's brother. After neglecting sleep, she collapses and awakens inside the game as the villainess, Ekaterina. Now the sister of her favorite character, Alexei, she is delighted to be close to him. However, she soon realizes that following the game's original path leads to a grim fate for her and her brother. Ekaterina must find a way to avert the impending doom threatening her new family and their empire while also trying to prevent Alexei from overworking himself.