As an aesthetic experiment, I was reading and comparing the light novel and the manga. Both, of course, in translation. The central idea here is the Japanese heroine was reborn in a dating game. As the villainess. Apparently a rather popular subgenre.
Set in a high fantasy world containing elements of medieval Europe, the 19th century, Japanese culture, and classic high fantasy tropes, but mixed together fairly smoothly.
Absolutely no explanation how the reborn effect came about
She's eight years old when she remembers -- about to become engaged to a prince who will kill or exile her in one path -- and, panicking, tries to figure out ways to survive, even though in the game, she will, in seven years, go to magical school and torment the heroine. Not just the path with the prince, but other "capture targets" for the heroine: the distant cousin that her father adopts because she will marry the prince; the twin of the first cousin, the son of the royal chancellor.
Sweet and dramatic moments. But while she tends to be passionately focused on single ideas and often doesn't realize what other consequences will be -- it produces many of the best moments -- she never notices much of the effects she has because she is certain that she's the villainess, despite the things she does, and the years she has to notice. Sometimes it's comic. Apparently other readers find more of it comic than I do. (Also, it doesn't seem consistent all the time, and I find it hard that years of doing such things don't have more effect on her character development.)
Manga vs. light novel -- well, the light novel moved along at good speed, which I have been unlucky about in my first samples. It also gave some sharp motivations and personality, which were intriguing, that the manga couldn't manage, and the manga adapted or omitted scenes, once or twice for the worse. But the light novel had the stupid failure to notice things more clearly. Also, there were a couple of moment when she was the point of view character but the text commented on her failure to notice things.