I recommend you to read the two novels, Naruto Dynasty and In a Different World. "Naruto Dynasty" was a novel based on an infinite ninja manga. It told the story of some students who were chosen to be reincarnators of infinite space and completed difficult missions in the Ninja Continent. "In the Other World" was a first-person story about the main character, Hikiya Hachiman. It told the story of his constant entanglements and conflicts. I hope you like my recommendation. Muah ~