Once I was reborn as the Prince of the North

To be reborn as the son of the main protagonist of the novel she read before she died is not something a teenage girl dreams of. It's a good thing that it's a prince. The bad thing is his destiny... Instead of accepting it or starting to rewrite the plot in her favor, the heroine (or in this case, the hero) is looking for a way to get back to the world with the Internet and her grandparents.