Enlightened Empire - Chapter 408: Instinct

In the back of the forest lives Allen, the antisocial wizard. He is feared by the people around him and called the “Demon Lord”.One day, while living out his life as a hermit, he finds a young girl named Charlotte who collapsed. Although innocent, she was accused of evil wrongdoings, had her engagement broken and was forced to flee her country.Upon hearing that, Allen recalled the bitter experience of being betrayed by a party he once believed to be his companions. Hearing the story of the 17 year old’s exploitation, Allen decides, “I’ll let her live in my mansion, and I’ll teach her all sorts of bad things…”

She shouldn’t have got drunk, so she wouldn’t have court the troubles.
She slept with a handsome man and would be sent to the police?
Oh, my sweet Jesus…
“So you just ran away like nothing happened after you slept with me?”
“Old jerk! Even if I had the initiative, it was you who took advantage of me!”
As a saying goes, the more spoiled a president gets, the more likely he becomes a scumbag.
An adorable ‘wildcat’ vs. a scheming frenemy.
This was a love rivalry between a modern Cinderella and a Big Boss.
As time flew, the world was like a fleeting show.
When they met again after several years of separation, he held her hand tightly and swore that he would never give her any chance to leave him again!
Finally, he asked her to marry him and pampered his cute wifey with his endless love.

- 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.

Welcome to Freia. A continent where evil magi ruled. Until firearms came, that is. Now the people live free of those demons…