Haikyuu: Zero To Almighty - Chapter 482: I’ll Be Waiting (Double-Length)

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?”

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

He holds a god-level sign-in system in his hand, punches the goose factory, and steps on the pig factory. Do you think there is no good game?
First feed you two mouthfuls of tainted milk powder, and then send you the legend of the dragon and the Hearthstone gold cartoon for free.
What? Still not satisfied? League of Kings out-of-print skin, give away!
Satisfied? Tch, this is just the beginning…

- Description from novelbuddy