The Godsfall Chronicles - Book 1, Chapter 15 A Bloody Party

Opening her eyes, Qiao Sang found that she was dressed as a junior high school student.

Then came a mock test.

Is she afraid of 985 graduation?

She was afraid…

What is the test for?

What is the name of the final evolved form of the Stinky Loach?

What planets have humans colonized?

…

Welcome to the world of beast control.

- Description from novelbuddy

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.

Ye Song, who once lived in a technologically-advanced world, died and reincarnated into a noble teenager’s body in another world.

A fantasy world filled with magic!

A series of events filled with tragedy, action, etc. began to unfold one after the other when he fatefully encountered one of the most guarded secrets of this world, obtaining the legendary power of Wizards.

Watch how he reaches unreachable heights as a powerful Wizard in this new world.

- Description from Novelupdates