This Japanese Monogatari Isn't Lame - Chapter 39. A Bit Like

During a party one evening in the royal palace, Rachel, the eldest daughter of Duke Ferguson, was reproached by Prince Elliot for sins she didn’t remember committing and their engagement was abandoned. Rachel informed everyone she had not committed the acts they were accusing her of, but she was dragged away out of the party venue and thrown into the palace dungeon.

“Is this man not going to divorce me? Why does he still ask me to warm the bed every night?”

A certain man said this was due to the winter being too cold. However, when summer finally arrived, she still needed to warm the bed, thus a certain girl could not take it anymore:

“I want a divorce!”

A certain man only smiled wantonly and said, “Divorce? Sure, as long as you agree to two conditions of mine.”

“What conditions?”

“Either you pamper me or I pamper you, the duration is ten thousand years…..”

- Description from Novelupdates

SLASH!(So this is death?!!)I, Elysia, found myself dead before even reaching the Demon King's lair, and our Hero Party was completely annihilated.And this was done by none other than a fellow human—my former classmate.He had been mostly invisible during our time at the academy, but then he started committing one crime after another until he became a lackey of the Demon King.Who would have thought that the strongest party of humanity would be wiped out by humanity’s traitors?(If I could go back to the past, I swear I will kill you!)Just when I thought I could finally pass on, I opened my eyes.Five years back, when I first enrolled at Arcadia Academy.And there he was, the traitorous bastard of humanity...****“Huh? Where am I?”One day, I opened my eyes to find myself in an unfamiliar place and came to realize this was the world within the novel Savior's Dawn that I had read.Everything seemed to be proceeding the same as in the novel—except for one thing.The main heroine is glaring at me as though she wants to kill me.Could I survive with the main heroine after my life?

Her – a glutton without troubles or worries who crossed over and became a young fat chick with a deep vengefulness.