The Demon Queen's Contract - Chapter 1: The End of One Life

A fickle, decadent, wilful person going through life like it’s a game.

An experienced, logical mind that’s above feelings.

This was a relationship that had started off with “Carpe Diem”, but slowly turned into a bloodless, psychological battle. They shared a mutual distrust, but also mutual attraction. As they suspected and tested each other, challenging each other’s limits, they both fell into the enemy’s hands with their eyes wide open. Sentiments growing amidst ignorance, they finally, were caught in their own traps.

Winner takes all,

Loser stands small.

- Description from Novelupdates

An Jing had transmigrated into the body of an ancient farm girl whom everyone could bully.On the day she crossed over, she was sold. Alright, seizing the servitude contract, stepping on her good-for-nothing parents, she held her freedom in her grasp, she was in charge of her marriage, she called the shots for her future—nobody could point fingers at her!An Jing assertively slapped her servitude contract onto the man beside her, “Keep it safe, from now on I belong to you.”The man: “......”The man doted on her. Whatever she wanted to do, she did, and they even teamed up to torment all sorts of scum. The couple's life was incredibly satisfying.It's just that the man's identity...(A gratifying story, with both strong male and female leads, 1v1 pampering)

Who needs a Class when you're already the strongest anyways?Ten years ago, Amelia woke up alone and lost in a broken world where she had to fight for her survival.Now, after reaching the pinnacle of power, defeating the Void itself, and escaping the abyss, she has finally found her way back into the real world. But instead of returning to Earth, she arrives in the land of Vacuos. A fantasy world with magic, monsters, Classes, and Levels. A world that is governed by a System like it were a video game.And when rewarded with a Class befitting her accomplishments— to become a powerful [Hero] that will forever dedicate her life to protecting this world that is not her own— she only has one response.“Absolutely not. I’m going to live a normal life now, thank you very much.”

There’s a legendary Bishoujo Game that has become popular among Japanese gentlemen.