Blackstone Code - Chapter 197:

Kira was living the life that others could only dream about. He was gorgeous, rich and very popular - the kind of guy that drew students from all over the place just so they could brag to others that they went to the same school as him. He was undoubtedly the number one heartthrob that every girl dreamed about.

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates

What if an alien baby born in the midst of a major conflict on another planet was sent to Earth to save his life? Born with intelligence and the ability to create technology from any material he touches, he was found by a couple in rural Japan and raised like a normal human.Despite his powers beyond reason, living in a peaceful world forced him to restrain himself. He grew up as a young man who loved high-tech superheroes, but never had the chance to realize his dream of becoming a hero.However, everything changed when he and his classmates were suddenly transported to another world—a world of monsters, war, and chaos. Seeing the helplessness of the humans in that world, he realized that this was the chance he had been waiting for.Not with magic, swords, or ordinary physical strength—he would become a hero with technological sophistication that surpassed any civilization!This will be Ren Takamura's story!

In a morgue filled with the bodies of Uchiha clan members, he opened his eyes...A mysterious voice echoed in his ears...With a bewildered expression, he muttered, “Save the Shinobi world? What does that have to do with me, a mere Uchiha survivor?”