Ichiban Ushiro no Daimaou - Volume 5, Chapter 5 — The Foreign Transfer Student

Xu Mo, a modern high school student was sent back in time to Jing Kingdom and found herself trapped inside of the body of a princess with the same name.

She had barely recovered when she learned of an unparalleled fiancé and in a daze, they got married. Then the stunning genius physician who normally does not pay attention clamoured to marry her. After that, there was a cold general, a flirtatious lord, a tsundere young master……

As it turns out, this was a male-dominated dynasty. Because the female population was sparse, the entire nation shared wives regardless of rank or nobility. Is it feasible for someone who wants to maintain monogamy in this dynasty?

- Description from Novelupdates

27-year-old Hisha, transmigrates into the body of a thousand-year-old overpowered supreme overlord who had everything at his disposal, except one–worthy companions by his side.

Hence, a tournament was held to choose the best out of the most beautiful, unique and strong women across the land.

These women don't follow the rule of coexisting women in a harem, they fight for the right to bed their lord and would stop at nothing but to use every opportunity to seduce, and fight on his behalf just to get his attention and favor.

Hisha never liked such a barbaric method of getting a companion.

'Why choose a few, if you can have them all?'

'If he can't have them all, he would try to work out coexisting the strongest for his pleasure and benefit.'

He realizes his 'Desire System' levels him up with every adoration gotten from his harem. The stronger they get, the higher his level and hold in his world.

As he continues to break his limits with the help of his harem, he finds out there are others that threaten his rule and the balance of his land.

'Let the tournament begin!'

[Host, host, I am the System, I can help you conquer the world and the witches with various personalities.]Xi Mu: Hmm... Isn't this an action game? When do we start slashing?[Right... This is an action game, but I suggest that the host also try to seduce the witches along the way, there are generous rewards.]Xi Mu: What rewards?[Of course, the perfect romantic experience!]Xi Mu: No need, I've already played through the romance plotlines. Now I just want to go on a rampage and speedrun the game.][...]

Utsuro no Hako to Zero no Maria, or The Empty Box and The Zeroth Maria, tells the sinister story of Kazuki Hoshino, who is almost madly attached to his everyday life, and his antagonist Aya Otonashi, who suddenly transfers into his class—for the 13,118th time. She majestically announces to “break” him, without paying heed to anyone else around them.