Rei traversed to the Naruto world, becoming an ordinary Chunin teacher at the Konoha Ninja Academy and a member of the Root organization. Fortunately, he awakened the Teacher System, where teaching made him stronger. To avoid becoming Danzo's expendable pawn, Rei diligently taught to enhance his strength. [The first time you completed an A-rated teaching session, you received a reward — mastery of Fire Release chakra nature transformation.] [Under your guidance, Uchiha Shisui trained hard, significantly improving his overall strength, and you received a reward — the Sage Body!] Through Rei's teachings, Shisui understood that the village's enemies were not necessarily from other nations; they could also be within the village. Those who preached the Will of Fire might not necessarily act according to it. Obito shed his last-place reputation at the Ninja Academy, and Might Guy became a Taijutsu expert even earlier... === I haven’t seen this story here so viola, tranlatin’ it. Don’t ask about harem or romance since it is pure story about politics and getting stronger. If you have another inquiry, leave a review or comments. I will surely answer. The cover isn’t mine! Heck, even the story isn’t mine! Even this laptop I am using isn’t mine!