Regressor Takes Everything - Chapter 131: Teach Only The Essentials (2)

Kazuki’s life was painfully average—just another cog in the nine-to-five grind. His only escape? Binge-reading novels and no-lifing video games.Then he woke up inside one of those novels.Armed with unstable morals, unhinged humor, and a penchant for pettiness, Kazuki is determined to survive, thrive, and maybe cause a little chaos along the way.The world has no idea what’s coming.

A boy from 21st century Earth, met an accident and later was reborn in Naruto’s Ninja World.
He is born in Uchiha Family and becomes the useless brother of Itachi Uchiha and Sasuke Uchiha…. Let’s see how he changed the Naruto world.

- Description from Novelupdates

In the twenty-seventh year of Hong Guang, the allied forces of seven nations invaded the Great Blue Dynasty.Rifled muskets, mortars, and armored vehicles combined into a steel tide, were ultimately shattered by the Great Blue's armored cavalry.Muscle, magic, firearms, cannons... the new and the old powers continuously collided.In an era of great strife, Li Fei, with the help of a Ten Thousand Blood Bead, gradually became an existence akin to a BOSS:'Is this the extent of your damage? You haven't even taken off one-thousandth of my health.''You don't think this is enough to kill me, do you?''Don't rush, the second phase is up next!'......

He died on the wedding of the girl he had a crush on, after a long and successful career. After convincing Yama to send him back to the world, he decides to fix the areas in which his life went wrong. Realizing the lack of love and romance in his past life, he sets out to conquer the hearts of various women.