The Number One Star in the Interstellar Era [BL] - Chapter 504 HOPELESSLY IN LOVE...

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

The world froze.Literally froze. The chattering students, the falling cherry blossoms outside the window, even the dust motes in the air – all suspended in perfect stillness.“Oh wonderful hero,” a melodious voice echoed through the room. “Your world faces a terrible crisis, and you have been chosen to—”“No,” he said flatly.A pause. Then a shimmer of golden light coalesced into the form of a beautiful woman in flowing robes. She blinked at him. “I... what?”“I said no. I'm not interested in whatever quest or destiny you're selling. Pick someone else.”The goddess's perfect features creased in confusion. “But... but you've been chosen! The prophecy speaks of a warrior with a fierce spirit, one who—”“Lady, I don't care about your prophecy. I've got enough problems here without adding some fantasy world's issues to the mix. Now un-freeze time and leave me alone.”“You don't understand,” she pressed. “Our world is being ravaged by the Demon King's armies! Millions will die without—”

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