Rebirth: I Became Mr.President's Beloved - Chapter 23 - How Did Mr. Song Come Here

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

As the newly appointed 12th Fatui Harbringer of Snezhnaya, with the nickname of the [Ausbilder], or The [Instructor], Bai Luo feels a little uneasy.This is because the Cryo Archon has given him a task: to go to Inazuma as the Snezhnaya Envoy.As a world traveler, he knows full well the consequences of going to Inazuma—he will definitely be targeted by Raiden Shogun.However, if he doesn't go, the Cryo Archon will also target him.So he chooses to employ a traditional technique that everyone tend to use from time to time in his previous world.Slacking off.

Surgeon Guan Ryo Is reborn in Naruto’s world! Enjoy his trip as he uses his knowledge of the story to find his path in this troubled world and eventually stand at the top of Konoha!

- Description from Novelupdates

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----