The First Magic World War - Chapter 455 - 423, there is no misunderstanding

Qiaosheng, you are the one who saves me, yet you are also the one who gives me hell. If we cannot grow old together, I’d rather we’ve never met before.

- Description from Novelupdates

I was the one who boosted your rank. Yet you stabbed me in the back? Fine. Goodbye. I’m taking it back. You’re finished now. Thanks to you, I now have an abundance of skill points for a prosperous hunter life. But… after spending some of those points, the S-Rank is starting to get obsessed with me…?

Calamity descends upon a a tranquil world in the black of night, transforming it into a death game! This a a true apocalypse, but this is not the end of humanity!

- Description from Novelupdates

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.