Well, the 'mirai nikki visual novel' generally follows the story of the anime. It has elements of psychological thriller. The characters are in a battle royale - like situation, with their diaries being their most important asset. They have to outwit and outmaneuver each other to become the sole survivor in this strange and dangerous world.
I'm not sure who Nikki Yovino is just based on this title. She could be the author of the story, in which case she might be a writer or storyteller. She might be writing from her own experiences or from her imagination.
" Naruto Mirai Forum Tang Erbai " was a website that mainly shared Naruto-related resources. The website contained a large number of unauthorized Naruto manga, novels, animations, and other works. The distribution of these works violated the copyright of the original author.
While waiting for the anime, you can also click on the link below to read the classic original work of " Full-time Expert "!
It's hard to say for sure. Some of the stories might be based on real events, but they could also be exaggerated or fictionalized for entertainment purposes.