The Empress's No.1 Lackey - Chapter 624 - 436, In early summer that year, standing inside the Imperial Palace, like a lackey (5k)_3

A former sporting rifle shooter genius transforms into the ‘Juvenile Butcher’. While originally supposed to have received the death penalty, he was instead fortunate enough to have entered a secret and highly regarded armed force, throwing himself into the ‘Nirvana Project’.

I became a side-character who died in anguish because of her good-for-nothing husband.

If I can’t avoid getting married, why don’t I change who I marry instead?

“Excellent, marriage sounds good.”

“Wise choice. Then let’s have a wedding ceremony that isn’t too ceremonious. Following that, I’ll need you to go down to the Fief and behave like the lady of the house until I call for you. Naturally, there won’t be any time to spend in leisure whilst dousing yourself in luxuries.”

“I’m not marrying you, but your father instead.”

“……Pardon?”

“I’m not going to marry you. Do you have a problem with that?”

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.