Himekishi ga Classmate Isekai Cheat de Dorei ka Harem - Chapter 44: The End of the Feast and The Strongest Title Part 2

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 protagonist of the world where Lev Razanov lived had already achieved his happy ending. Meanwhile, the world continued to move forward. Until the protagonist betrayed humanity.[You have been killed by the main character.][Hero’s System successfully installed.][Do you wish to return to the past?]Lev was given a chance to return to a time when the story of his favorite novel had just begun.Although he was destined to become an extra villain—a pawn of the pawns serving the real villain, he vowed to end the lives of anyone who had caused him suffering.[Hero’s System inherits your desire from your life on Earth—the desire to do good.]“Who said killing your enemies is an evil act?”[You gain +10 kill points.][You gain +10 heroic points.]***Additional Tags: Second Chance, Past Play a Big Role, Game Elements, Handsome Male Lead.(Third Person Limited Pov.)

However, he did not know that he was not raising just a harmless pet, but a biological weapon secretly made by the government… a real monster.

As a former librarian, Rand felt that he had been living an ordinary life, the one that he had reclaimed unconsciously every single day.

Recently, he has been a little upset because the pet fish he accidently brought home to raised seems to have undergo some strange changes

Well, it turned into a merman.

- 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.